Provided by: zsh-common_5.1.1-1ubuntu2.3_all bug

NAME

       zshmodules - zsh loadable modules

DESCRIPTION

       Some  optional  parts  of zsh are in modules, separate from the core of the shell.  Each of these modules
       may be linked in to the shell at build time, or can be dynamically linked while the shell is  running  if
       the  installation  supports  this  feature.  Modules are linked at runtime with the zmodload command, see
       zshbuiltins(1).

       The modules that are bundled with the zsh distribution are:

       zsh/attr
              Builtins for manipulating extended attributes (xattr).

       zsh/cap
              Builtins for manipulating POSIX.1e (POSIX.6) capability (privilege) sets.

       zsh/clone
              A builtin that can clone a running shell onto another terminal.

       zsh/compctl
              The compctl builtin for controlling completion.

       zsh/complete
              The basic completion code.

       zsh/complist
              Completion listing extensions.

       zsh/computil
              A module with utility builtins needed for the shell function based completion system.

       zsh/curses
              curses windowing commands

       zsh/datetime
              Some date/time commands and parameters.

       zsh/db/gdbm
              Builtins for managing associative array parameters tied to GDBM databases.

       zsh/deltochar
              A ZLE function duplicating EMACS' zap-to-char.

       zsh/example
              An example of how to write a module.

       zsh/files
              Some basic file manipulation commands as builtins.

       zsh/langinfo
              Interface to locale information.

       zsh/mapfile
              Access to external files via a special associative array.

       zsh/mathfunc
              Standard scientific functions for use in mathematical evaluations.

       zsh/newuser
              Arrange for files for new users to be installed.

       zsh/parameter
              Access to internal hash tables via special associative arrays.

       zsh/pcre
              Interface to the PCRE library.

       zsh/regex
              Interface to the POSIX regex library.

       zsh/sched
              A builtin that provides a timed execution facility within the shell.

       zsh/net/socket
              Manipulation of Unix domain sockets

       zsh/stat
              A builtin command interface to the stat system call.

       zsh/system
              A builtin interface to various low-level system features.

       zsh/net/tcp
              Manipulation of TCP sockets

       zsh/termcap
              Interface to the termcap database.

       zsh/terminfo
              Interface to the terminfo database.

       zsh/zftp
              A builtin FTP client.

       zsh/zle
              The Zsh Line Editor, including the bindkey and vared builtins.

       zsh/zleparameter
              Access to internals of the Zsh Line Editor via parameters.

       zsh/zprof
              A module allowing profiling for shell functions.

       zsh/zpty
              A builtin for starting a command in a pseudo-terminal.

       zsh/zselect
              Block and return when file descriptors are ready.

       zsh/zutil
              Some utility builtins, e.g. the one for supporting configuration via styles.

THE ZSH/ATTR MODULE

       The zsh/attr module is used for manipulating extended attributes.  The -h option causes all  commands  to
       operate on symbolic links instead of their targets.  The builtins in this module are:

       zgetattr [ -h ] filename attribute [ parameter ]
              Get  the  extended  attribute  attribute  from  the  specified  filename. If the optional argument
              parameter is given, the attribute is set on that parameter instead of being printed to stdout.

       zsetattr [ -h ] filename attribute value
              Set the extended attribute attribute on the specified filename to value.

       zdelattr [ -h ] filename attribute
              Remove the extended attribute attribute from the specified filename.

       zlistattr [ -h ] filename [ parameter ]
              List the extended attributes currently set on the specified filename.  If  the  optional  argument
              parameter  is  given,  the list of attributes is set on that parameter instead of being printed to
              stdout.

       zgetattr and zlistattr allocate memory dynamically.  If the attribute or list of attributes grows between
       the allocation and the call to get them, they return 2.  On all other errors, 1 is returned.  This allows
       the calling function to check for this case and retry.

THE ZSH/CAP MODULE

       The zsh/cap module is used for manipulating POSIX.1e (POSIX.6) capability sets.  If the operating  system
       does  not  support  this interface, the builtins defined by this module will do nothing.  The builtins in
       this module are:

       cap [ capabilities ]
              Change the shell's process capability sets to the specified capabilities,  otherwise  display  the
              shell's current capabilities.

       getcap filename ...
              This  is a built-in implementation of the POSIX standard utility.  It displays the capability sets
              on each specified filename.

       setcap capabilities filename ...
              This is a built-in implementation of the POSIX standard utility.  It sets the capability  sets  on
              each specified filename to the specified capabilities.

THE ZSH/CLONE MODULE

       The zsh/clone module makes available one builtin command:

       clone tty
              Creates  a forked instance of the current shell, attached to the specified tty.  In the new shell,
              the PID, PPID and TTY special parameters are changed appropriately.  $! is set to zero in the  new
              shell, and to the new shell's PID in the original shell.

              The return status of the builtin is zero in both shells if successful, and non-zero on error.

              The  target  of clone should be an unused terminal, such as an unused virtual console or a virtual
              terminal created by

                     xterm -e sh -c 'trap : INT QUIT TSTP; tty;
                             while :; do sleep 100000000; done'

              Some words of explanation are warranted about this long xterm command line: when doing clone on  a
              pseudo-terminal,  some  other session ("session" meant as a unix session group, or SID) is already
              owning the terminal. Hence the cloned zsh cannot acquire the pseudo-terminal as a controlling tty.
              That means two things:

              •      the job control signals will go to the sh-started-by-xterm process  group  (that's  why  we
                     disable  INT  QUIT  and  TSTP  with  trap;  otherwise the while loop could get suspended or
                     killed)

              •      the cloned shell will have job control disabled,  and  the  job  control  keys  (control-C,
                     control-\ and control-Z) will not work.

              This does not apply when cloning to an unused vc.

              Cloning  to  a  used (and unprepared) terminal will result in two processes reading simultaneously
              from the same terminal, with input bytes going randomly to either process.

              clone is mostly useful as a shell built-in replacement for openvt.

THE ZSH/COMPCTL MODULE

       The zsh/compctl module makes available two builtin commands. compctl,  is  the  old,  deprecated  way  to
       control  completions  for  ZLE.   See  zshcompctl(1).  The other builtin command, compcall can be used in
       user-defined completion widgets, see zshcompwid(1).

THE ZSH/COMPLETE MODULE

       The zsh/complete module makes available several builtin  commands  which  can  be  used  in  user-defined
       completion widgets, see zshcompwid(1).

THE ZSH/COMPLIST MODULE

       The  zsh/complist module offers three extensions to completion listings: the ability to highlight matches
       in such a list, the ability to scroll through long lists and a different style of menu completion.

   Colored completion listings
       Whenever one of the parameters ZLS_COLORS or ZLS_COLOURS is set and the zsh/complist module is loaded  or
       linked  into  the  shell,  completion  lists  will  be  colored.   Note,  however, that complist will not
       automatically be loaded if it is not linked in:  on systems with dynamic loading, `zmodload zsh/complist'
       is required.

       The parameters ZLS_COLORS and ZLS_COLOURS describe how matches are highlighted.  To turn on  highlighting
       an  empty  value  suffices, in which case all the default values given below will be used.  The format of
       the value of these parameters is the same as used by the GNU version of the ls command: a colon-separated
       list of specifications of the form `name=value'.  The name may be one of the following strings,  most  of
       which specify file types for which the value will be used.  The strings and their default values are:

       no 0   for normal text (i.e. when displaying something other than a matched file)

       fi 0   for regular files

       di 32  for directories

       ln 36  for symbolic links.  If this has the special value target, symbolic links are dereferenced and the
              target file used to determine the display format.

       pi 31  for named pipes (FIFOs)

       so 33  for sockets

       bd 44;37
              for block devices

       cd 44;37
              for character devices

       or none
              for a symlink to nonexistent file (default is the value defined for ln)

       mi none
              for a non-existent file (default is the value defined for fi); this code is currently not used

       su 37;41
              for files with setuid bit set

       sg 30;43
              for files with setgid bit set

       tw 30;42
              for world writable directories with sticky bit set

       ow 34;43
              for world writable directories without sticky bit set

       sa none
              for  files  with  an  associated  suffix  alias;  this  is only tested after specific suffixes, as
              described below

       st 37;44
              for directories with sticky bit set but not world writable

       ex 35  for executable files

       lc \e[ for the left code (see below)

       rc m   for the right code

       tc 0   for the character indicating the file type  printed after filenames if the  LIST_TYPES  option  is
              set

       sp 0   for the spaces printed after matches to align the next column

       ec none
              for the end code

       Apart  from these strings, the name may also be an asterisk (`*') followed by any string. The value given
       for such a string will be used for all files whose name ends with the string.  The name may  also  be  an
       equals sign (`=') followed by a pattern; the EXTENDED_GLOB option will be turned on for evaluation of the
       pattern.   The  value  given  for  this  pattern  will be used for all matches (not just filenames) whose
       display string are matched by the pattern.  Definitions for the form with the  leading  equal  sign  take
       precedence  over  the values defined for file types, which in turn take precedence over the form with the
       leading asterisk (file extensions).

       The leading-equals form also allows different parts of the displayed strings to be  colored  differently.
       For  this, the pattern has to use the `(#b)' globbing flag and pairs of parentheses surrounding the parts
       of the strings that are to be colored differently.  In this case the value may consist of more  than  one
       color  code  separated  by  equal signs.  The first code will be used for all parts for which no explicit
       code is specified and the following codes will be used for the  parts  matched  by  the  sub-patterns  in
       parentheses.   For example, the specification `=(#b)(?)*(?)=0=3=7' will be used for all matches which are
       at least two characters long and will use the code  `3'  for  the  first  character,  `7'  for  the  last
       character and `0' for the rest.

       All three forms of name may be preceded by a pattern in parentheses.  If this is given, the value will be
       used  only  for  matches  in groups whose names are matched by the pattern given in the parentheses.  For
       example, `(g*)m*=43' highlights all matches beginning with `m' in groups  whose  names   begin  with  `g'
       using the color code `43'.  In case of the `lc', `rc', and `ec' codes, the group pattern is ignored.

       Note  also that all patterns are tried in the order in which they appear in the parameter value until the
       first one matches which is then used.

       When printing a match, the code prints the value of lc, the value for the file-type or the last  matching
       specification with a `*', the value of rc, the string to display for the match itself, and then the value
       of ec if that is defined or the values of lc, no, and rc if ec is not defined.

       The  default  values  are ISO 6429 (ANSI) compliant and can be used on vt100 compatible terminals such as
       xterms.  On monochrome terminals the default values will have no visible  effect.   The  colors  function
       from  the contribution can be used to get associative arrays containing the codes for ANSI terminals (see
       the section `Other Functions' in zshcontrib(1)).  For  example,  after  loading  colors,  one  could  use
       `$colors[red]'  to  get  the  code  for  foreground  color  red  and `$colors[bg-green]' for the code for
       background color green.

       If the completion system invoked by compinit is used, these parameters should not be set directly because
       the system controls them itself.  Instead,  the  list-colors  style  should  be  used  (see  the  section
       `Completion System Configuration' in zshcompsys(1)).

   Scrolling in completion listings
       To  enable  scrolling through a completion list, the LISTPROMPT parameter must be set.  Its value will be
       used as the prompt; if it is the empty string, a default prompt will be  used.   The  value  may  contain
       escapes  of the form `%x'.  It supports the escapes `%B', `%b', `%S', `%s', `%U', `%u', `%F', `%f', `%K',
       `%k' and `%{...%}' used also in shell prompts as well as three pairs of additional sequences: a  `%l'  or
       `%L'  is  replaced  by  the  number  of  the  last  line  shown and the total number of lines in the form
       `number/total'; a `%m' or `%M' is replaced with the number of the last match shown and the  total  number
       of  matches; and `%p' or `%P' is replaced with `Top', `Bottom' or the position of the first line shown in
       percent of the total number of lines, respectively.  In each of these cases the form with  the  uppercase
       letter  will  be  replaced  with  a  string  of  fixed  width, padded to the right with spaces, while the
       lowercase form will not be padded.

       If the parameter LISTPROMPT is set, the completion code will  not  ask  if  the  list  should  be  shown.
       Instead it immediately starts displaying the list, stopping after the first screenful, showing the prompt
       at  the bottom, waiting for a keypress after temporarily switching to the listscroll keymap.  Some of the
       zle functions have a special meaning while scrolling lists:

       send-break
              stops listing discarding the key pressed

       accept-line, down-history, down-line-or-history
       down-line-or-search, vi-down-line-or-history
              scrolls forward one line

       complete-word, menu-complete, expand-or-complete
       expand-or-complete-prefix, menu-complete-or-expand
              scrolls forward one screenful

       accept-search
              stop listing but take no other action

       Every other character stops listing and immediately processes the key as usual.   Any  key  that  is  not
       bound  in  the  listscroll  keymap or that is bound to undefined-key is looked up in the keymap currently
       selected.

       As for the ZLS_COLORS and ZLS_COLOURS parameters, LISTPROMPT should not be set directly  when  using  the
       shell function based completion system.  Instead, the list-prompt style should be used.

   Menu selection
       The  zsh/complist  module  also offers an alternative style of selecting matches from a list, called menu
       selection, which can be used if the shell is set up  to  return  to  the  last  prompt  after  showing  a
       completion list (see the ALWAYS_LAST_PROMPT option in zshoptions(1)).

       Menu  selection  can  be  invoked  directly  by the widget menu-select defined by this module.  This is a
       standard ZLE widget that can be bound to a key in the usual way as described in zshzle(1).

       Alternatively, the parameter MENUSELECT can be set to an integer,  which  gives  the  minimum  number  of
       matches  that  must  be  present  before  menu  selection is automatically turned on.  This second method
       requires that menu completion be started, either directly from a widget such as menu-complete, or due  to
       one  of  the  options  MENU_COMPLETE or AUTO_MENU being set.  If MENUSELECT is set, but is 0, 1 or empty,
       menu selection will always be started during an ambiguous menu completion.

       When using the completion system based on shell functions, the MENUSELECT parameter should  not  be  used
       (like the ZLS_COLORS and ZLS_COLOURS parameters described above).  Instead, the menu style should be used
       with the select=... keyword.

       After  menu  selection  is started, the matches will be listed. If there are more matches than fit on the
       screen, only the first screenful is shown.  The matches to insert into the command line can  be  selected
       from  this  list.   In  the  list  one match is highlighted using the value for ma from the ZLS_COLORS or
       ZLS_COLOURS parameter.  The default value for  this  is  `7'  which  forces  the  selected  match  to  be
       highlighted using standout mode on a vt100-compatible terminal.  If neither ZLS_COLORS nor ZLS_COLOURS is
       set, the same terminal control sequence as for the `%S' escape in prompts is used.

       If  there  are more matches than fit on the screen and the parameter MENUPROMPT is set, its value will be
       shown below the matches.  It supports the same escape sequences as LISTPROMPT,  but  the  number  of  the
       match  or line shown will be that of the one where the mark is placed.  If its value is the empty string,
       a default prompt will be used.

       The MENUSCROLL parameter can be used to specify how the list is scrolled.  If  the  parameter  is  unset,
       this  is  done line by line, if it is set to `0' (zero), the list will scroll half the number of lines of
       the screen.  If the value is positive, it gives the number of lines to scroll and if it is negative,  the
       list will be scrolled the number of lines of the screen minus the (absolute) value.

       As for the ZLS_COLORS, ZLS_COLOURS and LISTPROMPT parameters, neither MENUPROMPT nor MENUSCROLL should be
       set  directly  when  using  the  shell  function based completion system.  Instead, the select-prompt and
       select-scroll styles should be used.

       The completion code sometimes decides not to show all of the matches in the list.  These  hidden  matches
       are  either matches for which the completion function which added them explicitly requested that they not
       appear in the list (using the -n option of the  compadd  builtin  command)  or  they  are  matches  which
       duplicate a string already in the list (because they differ only in things like prefixes or suffixes that
       are  not  displayed).  In the list used for menu selection, however, even these matches are shown so that
       it is possible to select them.  To highlight such matches the hi and du capabilities  in  the  ZLS_COLORS
       and ZLS_COLOURS parameters are supported for hidden matches of the first and second kind, respectively.

       Selecting  matches  is  done  by  moving  the mark around using the zle movement functions.  When not all
       matches can be shown on the screen at the same time, the list will scroll up and down when  crossing  the
       top  or  bottom line.  The following zle functions have special meaning during menu selection.  Note that
       the following always perform the same task within the menu selection map and cannot be replaced  by  user
       defined widgets, nor can the set of functions be extended:

       accept-line, accept-search
              accept  the  current  match  and  leave  menu  selection  (but do not cause the command line to be
              accepted)

       send-break
              leaves menu selection and restores the previous contents of the command line

       redisplay, clear-screen
              execute their normal function without leaving menu selection

       accept-and-hold, accept-and-menu-complete
              accept the currently inserted match and continue selection allowing to select the  next  match  to
              insert into the line

       accept-and-infer-next-history
              accepts  the  current  match  and then tries completion with menu selection again;  in the case of
              files this allows one to select a directory and immediately attempt to complete files in  it;   if
              there  are  no  matches,  a  message is shown and one can use undo to go back to completion on the
              previous level, every other key leaves menu selection (including the other zle functions which are
              otherwise special during menu selection)

       undo   removes matches inserted during the menu selection by one of the three functions before

       down-history, down-line-or-history
       vi-down-line-or-history,  down-line-or-search
              moves the mark one line down

       up-history, up-line-or-history
       vi-up-line-or-history, up-line-or-search
              moves the mark one line up

       forward-char, vi-forward-char
              moves the mark one column right

       backward-char, vi-backward-char
              moves the mark one column left

       forward-word, vi-forward-word
       vi-forward-word-end, emacs-forward-word
              moves the mark one screenful down

       backward-word, vi-backward-word, emacs-backward-word
              moves the mark one screenful up

       vi-forward-blank-word, vi-forward-blank-word-end
              moves the mark to the first line of the next group of matches

       vi-backward-blank-word
              moves the mark to the last line of the previous group of matches

       beginning-of-history
              moves the mark to the first line

       end-of-history
              moves the mark to the last line

       beginning-of-buffer-or-history, beginning-of-line
       beginning-of-line-hist, vi-beginning-of-line
              moves the mark to the leftmost column

       end-of-buffer-or-history, end-of-line
       end-of-line-hist, vi-end-of-line
              moves the mark to the rightmost column

       complete-word, menu-complete, expand-or-complete
       expand-or-complete-prefix, menu-expand-or-complete
              moves the mark to the next match

       reverse-menu-complete
              moves the mark to the previous match

       vi-insert
              this toggles between  normal  and  interactive  mode;  in  interactive  mode  the  keys  bound  to
              self-insert  and  self-insert-unmeta  insert  into  the command line as in normal editing mode but
              without leaving menu selection; after each character  completion  is  tried  again  and  the  list
              changes  to  contain  only  the  new  matches; the completion widgets make the longest unambiguous
              string be inserted in the command line and undo and backward-delete-char go back to  the  previous
              set of matches

       history-incremental-search-forward
       history-incremental-search-backward
              this  starts  incremental searches in the list of completions displayed; in this mode, accept-line
              only leaves incremental search, going back to the normal menu selection mode

       All movement functions wrap around at the edges; any other zle function not listed leaves menu  selection
       and  executes  that  function.  It is possible to make widgets in the above list do the same by using the
       form of the widget with a `.' in front.  For example, the widget `.accept-line' has the effect of leaving
       menu selection and accepting the entire command line.

       During this selection the widget uses the keymap menuselect.  Any key that is not defined in this  keymap
       or  that is bound to undefined-key is looked up in the keymap currently selected.  This is used to ensure
       that the most important keys used during selection  (namely  the  cursor  keys,  return,  and  TAB)  have
       sensible  defaults.   However,  keys  in the menuselect keymap can be modified directly using the bindkey
       builtin command (see zshmodules(1)). For example, to make the return key  leave  menu  selection  without
       accepting the match currently selected one could call

              bindkey -M menuselect '^M' send-break

       after loading the zsh/complist module.

THE ZSH/COMPUTIL MODULE

       The  zsh/computil  module adds several builtin commands that are used by some of the completion functions
       in the completion system based on shell functions (see  zshcompsys(1)  ).   Except  for  compquote  these
       builtin  commands  are  very  specialised  and thus not very interesting when writing your own completion
       functions.  In summary, these builtin commands are:

       comparguments
              This is used by the _arguments function to  do  the  argument  and  command  line  parsing.   Like
              compdescribe  it has an option -i to do the parsing and initialize some internal state and various
              options to access the state information to decide what should be completed.

       compdescribe
              This is used by the _describe function to build the displays  for  the  matches  and  to  get  the
              strings  to  add  as  matches  with  their options.  On the first call one of the options -i or -I
              should be supplied as the first  argument.   In  the  first  case,  display  strings  without  the
              descriptions  will  be generated, in the second case, the string used to separate the matches from
              their descriptions must be given as the second argument and the  descriptions  (if  any)  will  be
              shown.  All other arguments are like the definition arguments to _describe itself.

              Once compdescribe has been called with either the -i or the -I option, it can be repeatedly called
              with  the -g option and the names of four parameters as its arguments.  This will step through the
              different sets of matches and store the value of compstate[list] in the first scalar, the  options
              for  compadd  in the second array, the matches in the third array, and the strings to be displayed
              in the completion listing in the fourth array.  The arrays may then be directly given  to  compadd
              to register the matches with the completion code.

       compfiles
              Used by the _path_files function to optimize complex recursive filename generation (globbing).  It
              does  three  things.  With the -p and -P options it builds the glob patterns to use, including the
              paths already handled and trying to optimize the patterns with respect to the  prefix  and  suffix
              from  the line and the match specification currently used.  The -i option does the directory tests
              for the ignore-parents style and the -r option tests if a component for some of  the  matches  are
              equal to the string on the line and removes all other matches if that is true.

       compgroups
              Used  by  the _tags function to implement the internals of the group-order style.  This only takes
              its arguments as names of completion groups and creates the groups for it (all six  types:  sorted
              and  unsorted,  both  without  removing duplicates, with removing all duplicates and with removing
              consecutive duplicates).

       compquote [ -p ] names ...
              There may be reasons to write completion functions that have to  add  the  matches  using  the  -Q
              option  to compadd and perform quoting themselves.  Instead of interpreting the first character of
              the all_quotes key of the compstate special  association  and  using  the  q  flag  for  parameter
              expansions,  one  can  use  this  builtin command.  The arguments are the names of scalar or array
              parameters and the values of these parameters are quoted  as  needed  for  the  innermost  quoting
              level.  If the -p option is given, quoting is done as if there is some prefix before the values of
              the parameters, so that a leading equal sign will not be quoted.

              The return status is non-zero in case of an error and zero otherwise.

       comptags
       comptry
              These implement the internals of the tags mechanism.

       compvalues
              Like comparguments, but for the _values function.

THE ZSH/CURSES MODULE

       The zsh/curses module makes available one builtin command and various parameters.

   Builtin
       zcurses init
       zcurses end
       zcurses addwin targetwin nlines ncols begin_y begin_x [ parentwin ]
       zcurses delwin targetwin
       zcurses refresh [ targetwin ... ]
       zcurses touch targetwin ...
       zcurses move targetwin new_y new_x
       zcurses clear targetwin [ redraw | eol | bot ]
       zcurses position targetwin array
       zcurses char targetwin character
       zcurses string targetwin string
       zcurses border targetwin border
       zcurses attr targetwin [ [+|-]attribute | fg_col/bg_col ] [...]
       zcurses bg targetwin [ [+|-]attribute | fg_col/bg_col | @char ] [...]
       zcurses scroll targetwin [ on | off | [+|-]lines ]
       zcurses input targetwin [ param [ kparam [ mparam ] ] ]
       zcurses mouse [ delay num | [+|-]motion ]
       zcurses timeout targetwin intval
       zcurses querychar targetwin [ param ]
              Manipulate  curses  windows.   All  uses  of this command should be bracketed by `zcurses init' to
              initialise use of curses, and `zcurses end' to end  it;  omitting  `zcurses  end'  can  cause  the
              terminal to be in an unwanted state.

              The subcommand addwin creates a window with nlines lines and ncols columns.  Its upper left corner
              will  be placed at row begin_y and column begin_x of the screen.  targetwin is a string and refers
              to the name of a window that is not currently assigned.  Note in particular the curses  convention
              that vertical values appear before horizontal values.

              If  addwin  is  given  an  existing  window  as the final argument, the new window is created as a
              subwindow of parentwin.  This differs from an ordinary new window in that the memory of the window
              contents is shared with the parent's memory.  Subwindows must  be  deleted  before  their  parent.
              Note  that the coordinates of subwindows are relative to the screen, not the parent, as with other
              windows.

              Use the subcommand delwin to delete a  window  created  with  addwin.   Note  that  end  does  not
              implicitly delete windows, and that delwin does not erase the screen image of the window.

              The  window  corresponding  to  the  full  visible screen is called stdscr; it always exists after
              `zcurses init' and cannot be delete with delwin.

              The subcommand refresh will refresh window targetwin;  this  is  necessary  to  make  any  pending
              changes  (such  as  characters  you  have  prepared  for  output with char) visible on the screen.
              refresh without an argument causes the screen to be cleared and redrawn.  If multiple windows  are
              given, the screen is updated once at the end.

              The  subcommand touch marks the targetwins listed as changed.  This is necessary before refreshing
              windows if a window that was in front of another window (which may be stdscr) is deleted.

              The subcommand move moves the cursor position in targetwin to new  coordinates  new_y  and  new_x.
              Note  that  the  subcommand string (but not the subcommand char) advances the cursor position over
              the characters added.

              The subcommand clear erases the contents of targetwin.  One  (and  no  more  than  one)  of  three
              options  may be specified.  With the option redraw, in addition the next refresh of targetwin will
              cause the screen to be cleared and repainted.  With the option eol, targetwin is only  cleared  to
              the  end  of the current cursor line.  With the option bot, targetwin is cleared to the end of the
              window, i.e everything to the right and below the cursor is cleared.

              The subcommand position writes various positions associated with targetwin into  the  array  named
              array.  These are, in order:
              -      The y and x coordinates of the cursor relative to the top left of targetwin
              -      The y and x coordinates of the top left of targetwin on the screen
              -      The size of targetwin in y and x dimensions.

              Outputting characters and strings are achieved by char and string respectively.

              To  draw  a  border around window targetwin, use border.  Note that the border is not subsequently
              handled specially:  in other words, the border is simply a set of characters output at the edge of
              the window.  Hence it can be overwritten, can scroll off the window, etc.

              The subcommand attr will set targetwin's attributes or foreground/background color  pair  for  any
              successive character output.  Each attribute given on the line may be prepended by a + to set or a
              - to unset that attribute; + is assumed if absent.  The attributes supported are blink, bold, dim,
              reverse, standout, and underline.

              Each fg_col/bg_col attribute (to be read as `fg_col on bg_col') sets the foreground and background
              color  for  character  output.   The  color  default  is sometimes available (in particular if the
              library is ncurses), specifying the  foreground  or  background  color  with  which  the  terminal
              started.  The color pair default/default is always available.

              bg  overrides the color and other attributes of all characters in the window.  Its usual use is to
              set the background initially, but it will overwrite the attributes of any characters at  the  time
              when  it is called.  In addition to the arguments allowed with attr, an argument @char specifies a
              character to be shown in otherwise blank areas of the window.  Owing to limitations of curses this
              cannot be a multibyte character (use of ASCII characters only is recommended).  As  the  specified
              set of attributes override the existing background, turning attributes off in the arguments is not
              useful, though this does not cause an error.

              The  subcommand scroll can be used with on or off to enabled or disable scrolling of a window when
              the cursor would otherwise move below the window due to typing or output.  It  can  also  be  used
              with  a  positive  or  negative  integer to scroll the window up or down the given number of lines
              without changing the current cursor position (which therefore appears  to  move  in  the  opposite
              direction  relative  to  the  window).   In the second case, if scrolling is off it is temporarily
              turned on to allow the window to be scrolled.

              The subcommand input reads a single character from the window without echoing it back.   If  param
              is supplied the character is assigned to the parameter param, else it is assigned to the parameter
              REPLY.

              If  both  param  and  kparam are supplied, the key is read in `keypad' mode.  In this mode special
              keys such as function keys and arrow keys return the name of the key in the parameter kparam.  The
              key names are the macros defined in the curses.h or ncurses.h with the prefix `KEY_' removed;  see
              also  the description of the parameter zcurses_keycodes below.  Other keys cause a value to be set
              in param as before.  On a successful return only one of  param  or  kparam  contains  a  non-empty
              string; the other is set to an empty string.

              If mparam is also supplied, input attempts to handle mouse input.  This is only available with the
              ncurses library; mouse handling can be detected by checking for the exit status of `zcurses mouse'
              with  no  arguments.   If  a  mouse button is clicked (or double- or triple-clicked, or pressed or
              released with a configurable delay from being clicked) then kparam is set to the string MOUSE, and
              mparam is set to an array consisting of the following elements:
              -      An identifier to discriminate different input devices; this is only rarely useful.
              -      The x, y and z coordinates of the mouse  click  relative  to  the  full  screen,  as  three
                     elements  in that order (i.e. the y coordinate is, unusually, after the x coordinate).  The
                     z coordinate is only available for a few unusual input devices  and  is  otherwise  set  to
                     zero.
              -      Any  events  that  occurred  as  separate  items; usually there will be just one.  An event
                     consists  of  PRESSED,  RELEASED,  CLICKED,  DOUBLE_CLICKED  or   TRIPLE_CLICKED   followed
                     immediately (in the same element) by the number of the button.
              -      If the shift key was pressed, the string SHIFT.
              -      If the control key was pressed, the string CTRL.
              -      If the alt key was pressed, the string ALT.

              Not  all mouse events may be passed through to the terminal window; most terminal emulators handle
              some mouse events themselves.  Note that the ncurses manual implies that using input both with and
              without mouse handling may cause the mouse cursor to appear and disappear.

              The subcommand mouse can be used to configure the use of the mouse.  There is no window  argument;
              mouse options are global.  `zcurses mouse' with no arguments returns status 0 if mouse handling is
              possible,  else  status  1.   Otherwise, the possible arguments (which may be combined on the same
              command line) are as follows.  delay num sets the maximum delay in milliseconds between press  and
              release events to be considered as a click; the value 0 disables click resolution, and the default
              is  one sixth of a second.  motion proceeded by an optional `+' (the default) or - turns on or off
              reporting of mouse motion in addition to clicks, presses and releases, which are always  reported.
              However, it appears reports for mouse motion are not currently implemented.

              The subcommand timeout specifies a timeout value for input from targetwin.  If intval is negative,
              `zcurses input' waits indefinitely for a character to be typed; this is the default.  If intval is
              zero,  `zcurses input' returns immediately; if there is typeahead it is returned, else no input is
              done and status 1 is returned.  If intval is positive, `zcurses input' waits  intval  milliseconds
              for input and if there is none at the end of that period returns status 1.

              The  subcommand querychar queries the character at the current cursor position.  The return values
              are stored in the array named param if supplied, else in the array reply.  The first value is  the
              character  (which  may  be  a  multibyte character if the system supports them); the second is the
              color pair in the usual fg_col/bg_col notation, or 0 if color is not  supported.   Any  attributes
              other  than  color  that  apply  to  the  character,  as  set  with the subcommand attr, appear as
              additional elements.

   Parameters
       ZCURSES_COLORS
              Readonly integer.  The maximum number of colors the terminal supports.  This value is  initialised
              by the curses library and is not available until the first time zcurses init is run.

       ZCURSES_COLOR_PAIRS
              Readonly integer.  The maximum number of color pairs fg_col/bg_col that may be defined in `zcurses
              attr' commands; note this limit applies to all color pairs that have been used whether or not they
              are  currently active.  This value is initialised by the curses library and is not available until
              the first time zcurses init is run.

       zcurses_attrs
              Readonly array.  The attributes supported by zsh/curses;  available  as  soon  as  the  module  is
              loaded.

       zcurses_colors
              Readonly array.  The colors supported by zsh/curses; available as soon as the module is loaded.

       zcurses_keycodes
              Readonly  array.   The  values  that  may be returned in the second parameter supplied to `zcurses
              input' in the order in which they are defined internally by curses.  Not  all  function  keys  are
              listed, only F0; curses reserves space for F0 up to F63.

       zcurses_windows
              Readonly  array.   The  current  list  of  windows,  i.e.  all windows that have been created with
              `zcurses addwin' and not removed with `zcurses delwin'.

THE ZSH/DATETIME MODULE

       The zsh/datetime module makes available one builtin command:

       strftime [ -s scalar ] format epochtime
       strftime -r [ -q ] [ -s scalar ] format timestring
              Output the date denoted by epochtime in the format specified.  See strftime(3) for  details.   The
              zsh  extensions  described  in  the  section  EXPANSION OF PROMPT SEQUENCES in zshmisc(1) are also
              available.

              -q     Run quietly; suppress printing of all error messages described below.  Errors  for  invalid
                     epochtime values are always printed.

              -r     With  the  option  -r (reverse), use format to parse the input string timestring and output
                     the number of seconds since  the  epoch  at  which  the  time  occurred.   The  parsing  is
                     implemented  by  the system function strptime; see strptime(3).  This means that zsh format
                     extensions are not available, but for reverse lookup they are not required.

                     In most implementations of strftime any timezone in the timestring is ignored and the local
                     timezone declared by the TZ environment variable is used; other parameters are set to  zero
                     if not present.

                     If  timestring  does  not  match  format  the  command returns status 1 and prints an error
                     message.  If timestring matches format but not all characters in timestring were used,  the
                     conversion succeeds but also prints an error message.

                     If either of the system functions strptime or mktime is not available, status 2 is returned
                     and an error message is printed.

              -s scalar
                     Assign  the  date  string  (or  epoch  time in seconds if -r is given) to scalar instead of
                     printing it.

              Note that depending on the system's declared integral time type, strftime  may  produce  incorrect
              results for epoch times greater than 2147483647 which corresponds to 2038-01-19 03:14:07 +0000.

       The zsh/datetime module makes available several parameters; all are readonly:

       EPOCHREALTIME
              A  floating point value representing the number of seconds since the epoch.  The notional accuracy
              is to nanoseconds if the clock_gettime call is available and to  microseconds  otherwise,  but  in
              practice  the  range  of  double  precision  floating  point and shell scheduling latencies may be
              significant effects.

       EPOCHSECONDS
              An integer value representing the number of seconds since the epoch.

       epochtime
              An array value containing the number of seconds since the epoch  in  the  first  element  and  the
              remainder  of  the  time  since the epoch in nanoseconds in the second element.  To ensure the two
              elements are  consistent  the  array  should  be  copied  or  otherwise  referenced  as  a  single
              substitution before the values are used.  The following idiom may be used:

                     for secs nsecs in $epochtime; do
                       ...
                     done

THE ZSH/DB/GDBM MODULE

       The  zsh/db/gdbm module is used to create "tied" associative arrays that interface to database files.  If
       the GDBM interface is not available, the builtins defined by this module  will  report  an  error.   This
       module  is  also intended as a prototype for creating additional database interfaces, so the ztie builtin
       may move to a more generic module in the future.

       The builtins in this module are:

       ztie -d db/gdbm -f filename [ -r ] arrayname
              Open the GDBM database identified by filename and, if successful,  create  the  associative  array
              arrayname linked to the file.  To create a local tied array, the parameter must first be declared,
              so commands similar to the following would be executed inside a function scope:

                     local -A sampledb
                     ztie -d db/gdbm -f sample.gdbm sampledb

              The  -r  option  opens  the database file for reading only, creating a parameter with the readonly
              attribute.  Without this option, using `ztie' on a file for which the user  does  not  have  write
              permission  is  an  error.  If writable, the database is opened synchronously so fields changed in
              arrayname are immediately written to filename.

              Changes to the file modes filename after it has been opened do not alter the state  of  arrayname,
              but `typeset -r arrayname' works as expected.

       zuntie [ -u ] arrayname ...
              Close  the  GDBM  database  associated  with  each arrayname and then unset the parameter.  The -u
              option forces an unset of parameters made readonly with `ztie -r'.

              This happens automatically if the parameter is explicitly unset  or  its  local  scope  (function)
              ends.   Note  that  a  readonly  parameter may not be explicitly unset, so the only way to unset a
              global parameter created with `ztie -r' is to use `zuntie -u'.

       The fields of an associative array tied to GDBM are neither cached nor otherwise stored in  memory,  they
       are  read from or written to the database on each reference.  Thus, for example, the values in a readonly
       array may be changed by a second writer of the same database file.

THE ZSH/DELTOCHAR MODULE

       The zsh/deltochar module makes available two ZLE functions:

       delete-to-char
              Read a character from the keyboard, and delete from the cursor position up to  and  including  the
              next  (or,  with repeat count n, the nth) instance of that character.  Negative repeat counts mean
              delete backwards.

       zap-to-char
              This behaves like delete-to-char, except that the final occurrence of the character itself is  not
              deleted.

THE ZSH/EXAMPLE MODULE

       The zsh/example module makes available one builtin command:

       example [ -flags ] [ args ... ]
              Displays the flags and arguments it is invoked with.

       The purpose of the module is to serve as an example of how to write a module.

THE ZSH/FILES MODULE

       The  zsh/files  module  makes  available  some  common  commands for file manipulation as builtins; these
       commands are probably not needed for many normal situations but  can  be  useful  in  emergency  recovery
       situations  with  constrained  resources.   The  commands  do  not implement all features now required by
       relevant standards committees.

       For all commands, a variant beginning zf_ is also available and loaded automatically.  Using the features
       capability of zmodload will let you load only those names you want.  Note that it's possible to load only
       the builtins with zsh-specific names using the following command:

              zmodload -m -F zsh/files b:zf_\*

       The commands loaded by default are:

       chgrp [ -hRs ] group filename ...
              Changes group of files specified.  This is equivalent  to  chown  with  a  user-spec  argument  of
              `:group'.

       chown [ -hRs ] user-spec filename ...
              Changes ownership and group of files specified.

              The user-spec can be in four forms:

              user   change owner to user; do not change group
              user:: change owner to user; do not change group
              user:  change owner to user; change group to user's primary group
              user:group
                     change owner to user; change group to group
              :group do not change owner; change group to group

              In each case, the `:' may instead be a `.'.  The rule is that if there is a `:' then the separator
              is `:', otherwise if there is a `.' then the separator is `.', otherwise there is no separator.

              Each  of user and group may be either a username (or group name, as appropriate) or a decimal user
              ID (group ID).  Interpretation as a name takes precedence, if there is an all-numeric username (or
              group name).

              If the target is a symbolic link, the -h option causes chown to set  the  ownership  of  the  link
              instead of its target.

              The  -R option causes chown to recursively descend into directories, changing the ownership of all
              files in the directory after changing the ownership of the directory itself.

              The -s option is a zsh extension to chown functionality.  It enables paranoid behaviour,  intended
              to  avoid  security  problems  involving a chown being tricked into affecting files other than the
              ones intended.  It will refuse to follow symbolic links,  so  that  (for  example)  ``chown  luser
              /tmp/foo/passwd''  can't  accidentally chown /etc/passwd if /tmp/foo happens to be a link to /etc.
              It will also check where it is after leaving directories, so that a  recursive  chown  of  a  deep
              directory  tree  can't  end up recursively chowning /usr as a result of directories being moved up
              the tree.

       ln [ -dfhins ] filename dest
       ln [ -dfhins ] filename ... dir
              Creates hard (or, with -s, symbolic) links.  In the  first  form,  the  specified  destination  is
              created,  as a link to the specified filename.  In the second form, each of the filenames is taken
              in turn, and linked to a pathname in the specified directory  that  has  the  same  last  pathname
              component.

              Normally,  ln  will not attempt to create hard links to directories.  This check can be overridden
              using the -d option.  Typically only the super-user can actually succeed in creating hard links to
              directories.  This does not apply to symbolic links in any case.

              By default, existing files cannot be replaced by links.  The -i  option  causes  the  user  to  be
              queried  about  replacing  existing  files.   The  -f  option causes existing files to be silently
              deleted, without querying.  -f takes precedence.

              The -h and -n options are identical and both exist for compatibility; either one indicates that if
              the target is a symlink then it should not be dereferenced.  Typically this is used in combination
              with -sf so that if an existing link points to a directory then it will  be  removed,  instead  of
              followed.   If  this  option  is  used  with  multiple filenames and the target is a symbolic link
              pointing to a directory then the result is an error.

       mkdir [ -p ] [ -m mode ] dir ...
              Creates directories.  With the -p option, non-existing parent directories  are  first  created  if
              necessary,  and  there will be no complaint if the directory already exists.  The -m option can be
              used to specify (in octal) a set of file permissions for the created directories,  otherwise  mode
              777 modified by the current umask (see umask(2)) is used.

       mv [ -fi ] filename dest
       mv [ -fi ] filename ... dir
              Moves files.  In the first form, the specified filename is moved to the specified destination.  In
              the  second form, each of the filenames is taken in turn, and moved to a pathname in the specified
              directory that has the same last pathname component.

              By default, the user will be queried before replacing any file that the user cannot write to,  but
              writable  files  will  be  silently  removed.   The  -i option causes the user to be queried about
              replacing any existing files.  The -f option causes any existing files  to  be  silently  deleted,
              without querying.  -f takes precedence.

              Note  that  this  mv  will  not move files across devices.  Historical versions of mv, when actual
              renaming is impossible, fall back on copying and removing files; if this behaviour is desired, use
              cp and rm manually.  This may change in a future version.

       rm [ -dfirs ] filename ...
              Removes files and directories specified.

              Normally, rm will not remove directories (except with the -r option).  The -d option causes rm  to
              try  removing  directories with unlink (see unlink(2)), the same method used for files.  Typically
              only the super-user can  actually  succeed  in  unlinking  directories  in  this  way.   -d  takes
              precedence over -r.

              By  default,  the user will be queried before removing any file that the user cannot write to, but
              writable files will be silently removed.  The -i option  causes  the  user  to  be  queried  about
              removing  any  files.   The  -f  option causes files to be silently deleted, without querying, and
              suppresses all error indications.  -f takes precedence.

              The -r option causes rm to recursively  descend  into  directories,  deleting  all  files  in  the
              directory before removing the directory with the rmdir system call (see rmdir(2)).

              The  -s option is a zsh extension to rm functionality.  It enables paranoid behaviour, intended to
              avoid common security problems involving a root-run rm being tricked  into  removing  files  other
              than  the  ones  intended.   It  will  refuse to follow symbolic links, so that (for example) ``rm
              /tmp/foo/passwd'' can't accidentally remove /etc/passwd if /tmp/foo happens to be a link to  /etc.
              It  will  also  check where it is after leaving directories, so that a recursive removal of a deep
              directory tree can't end up recursively removing /usr as a result of directories  being  moved  up
              the tree.

       rmdir dir ...
              Removes empty directories specified.

       sync   Calls  the  system  call  of the same name (see sync(2)), which flushes dirty buffers to disk.  It
              might return before the I/O has actually been completed.

THE ZSH/LANGINFO MODULE

       The zsh/langinfo module makes available one parameter:

       langinfo
              An associative array that maps langinfo elements to their values.

              Your implementation may support a number of the following keys:

              CODESET, D_T_FMT, D_FMT, T_FMT,  RADIXCHAR,  THOUSEP,  YESEXPR,  NOEXPR,  CRNCYSTR,  ABDAY_{1..7},
              DAY_{1..7},  ABMON_{1..12},  MON_{1..12}, T_FMT_AMPM, AM_STR, PM_STR, ERA, ERA_D_FMT, ERA_D_T_FMT,
              ERA_T_FMT, ALT_DIGITS

THE ZSH/MAPFILE MODULE

       The zsh/mapfile module provides one special associative array parameter of the same name.

       mapfile
              This associative array takes as keys the names of files; the resulting value is the content of the
              file.  The value is treated identically to any other text coming from a parameter.  The value  may
              also  be  assigned to, in which case the file in question is written (whether or not it originally
              existed); or an element may be unset, which will delete the file in question.  For example, `vared
              mapfile[myfile]' works as expected, editing the file `myfile'.

              When the array is accessed as a whole, the keys are the names of files in the  current  directory,
              and  the  values  are  empty (to save a huge overhead in memory).  Thus ${(k)mapfile} has the same
              affect as the glob operator *(D), since files beginning with a dot are not special.  Care must  be
              taken  with  expressions  such  as  rm  ${(k)mapfile}, which will delete every file in the current
              directory without the usual `rm *' test.

              The parameter mapfile may be made read-only; in that case, files referenced may not be written  or
              deleted.

              A  file  may  conveniently  be  read  into  an  array  as  one  line  per  element  with  the form
              `array=("${(f@)mapfile[filename]}")'.  The double quotes and the  `@'  are  necessary  to  prevent
              empty  lines  from being removed.  Note that if the file ends with a newline, the shell will split
              on the final newline, generating an additional empty  field;  this  can  be  suppressed  by  using
              `array=("${(f@)${mapfile[filename]%$'\n'}}")'.

   Limitations
       Although  reading  and  writing  of  the  file  in question is efficiently handled, zsh's internal memory
       management may be arbitrarily baroque; however, mapfile is usually very much more efficient than anything
       involving a loop.  Note in particular that the whole contents of the file will always  reside  physically
       in memory when accessed (possibly multiple times, due to standard parameter substitution operations).  In
       particular,  this  means  handling  of sufficiently long files (greater than the machine's swap space, or
       than the range of the pointer type) will be incorrect.

       No errors are printed or flagged for non-existent, unreadable, or  unwritable  files,  as  the  parameter
       mechanism is too low in the shell execution hierarchy to make this convenient.

       It  is unfortunate that the mechanism for loading modules does not yet allow the user to specify the name
       of the shell parameter to be given the special behaviour.

THE ZSH/MATHFUNC MODULE

       The zsh/mathfunc module provides standard mathematical functions for  use  when  evaluating  mathematical
       formulae.  The syntax agrees with normal C and FORTRAN conventions, for example,

              (( f = sin(0.3) ))

       assigns the sine of 0.3 to the parameter f.

       Most  functions  take floating point arguments and return a floating point value.  However, any necessary
       conversions from or to integer type will be performed automatically by the shell.  Apart from atan with a
       second argument and the abs, int and float functions, all functions behave as noted in  the  manual  page
       for  the  corresponding  C  function, except that any arguments out of range for the function in question
       will be detected by the shell and an error reported.

       The following functions take a single floating point argument: acos, acosh,  asin,  asinh,  atan,  atanh,
       cbrt,  ceil,  cos,  cosh,  erf,  erfc, exp, expm1, fabs, floor, gamma, j0, j1, lgamma, log, log10, log1p,
       logb, sin, sinh, sqrt, tan, tanh, y0, y1.  The atan function can optionally take a  second  argument,  in
       which  case  it  behaves  like  the  C  function atan2.  The ilogb function takes a single floating point
       argument, but returns an integer.

       The function signgam takes no arguments, and returns an integer, which is the  C  variable  of  the  same
       name,  as described in gamma(3).  Note that it is therefore only useful immediately after a call to gamma
       or lgamma.  Note also that `signgam()' and `signgam' are distinct expressions.

       The following functions take two floating point arguments: copysign, fmod, hypot, nextafter.

       The following take an integer first argument and a floating point second argument: jn, yn.

       The following take a floating point first argument and an integer second argument: ldexp, scalb.

       The function abs does not convert the type of its single argument;  it  returns  the  absolute  value  of
       either a floating point number or an integer.  The functions float and int convert their arguments into a
       floating point or integer value (by truncation) respectively.

       Note  that  the  C  pow function is available in ordinary math evaluation as the `**' operator and is not
       provided here.

       The function rand48 is available if your system's mathematical library has the function  erand48(3).   It
       returns  a  pseudo-random  floating  point  number  between  0  and 1.  It takes a single string optional
       argument.

       If the argument is not present, the random number seed is initialised  by  three  calls  to  the  rand(3)
       function --- this produces the same random numbers as the next three values of $RANDOM.

       If  the argument is present, it gives the name of a scalar parameter where the current random number seed
       will be stored.  On the first call, the value must  contain  at  least  twelve  hexadecimal  digits  (the
       remainder  of the string is ignored), or the seed will be initialised in the same manner as for a call to
       rand48 with no argument.  Subsequent calls to rand48(param) will then maintain the seed in the  parameter
       param  as a string of twelve hexadecimal digits, with no base signifier.  The random number sequences for
       different parameters are completely independent, and are also independent from  that  used  by  calls  to
       rand48 with no argument.

       For example, consider

              print $(( rand48(seed) ))
              print $(( rand48() ))
              print $(( rand48(seed) ))

       Assuming $seed does not exist, it will be initialised by the first call.  In the second call, the default
       seed  is  initialised;  note,  however,  that  because of the properties of rand() there is a correlation
       between the seeds used for the two initialisations, so for more secure uses, you should generate your own
       12-byte seed.  The third call returns to the same sequence of random numbers  used  in  the  first  call,
       unaffected by the intervening rand48().

THE ZSH/NEWUSER MODULE

       The  zsh/newuser  module  is loaded at boot if it is available, the RCS option is set, and the PRIVILEGED
       option is not set (all three are true by default).  This takes place immediately after  commands  in  the
       global  zshenv  file (typically /etc/zshenv), if any, have been executed.  If the module is not available
       it is silently ignored by the  shell;  the  module  may  safely  be  removed  from  $MODULE_PATH  by  the
       administrator if it is not required.

       On  loading, the module tests if any of the start-up files .zshenv, .zprofile, .zshrc or .zlogin exist in
       the directory given by the environment variable ZDOTDIR, or the user's home directory if that is not set.
       The test is not performed and the module halts processing if the shell was in an emulation mode (i.e. had
       been invoked as some other shell than zsh).

       If none of the start-up files were found, the module then looks for the file newuser first in a  sitewide
       directory,  usually  the  parent  directory of the site-functions directory, and if that is not found the
       module searches in a version-specific directory, usually the parent of the functions directory containing
       version-specific  functions.   (These  directories  can  be  configured  when  zsh  is  built  using  the
       --enable-site-scriptdir=dir and --enable-scriptdir=dir flags to configure, respectively; the defaults are
       prefix/share/zsh and prefix/share/zsh/$ZSH_VERSION where the default prefix is /usr/local.)

       If  the  file  newuser  is  found, it is then sourced in the same manner as a start-up file.  The file is
       expected to contain code to install start-up files for the user, however any valid  shell  code  will  be
       executed.

       The zsh/newuser module is then unconditionally unloaded.

       Note  that  it is possible to achieve exactly the same effect as the zsh/newuser module by adding code to
       /etc/zshenv.  The module exists simply to allow the shell to make arrangements for new users without  the
       need for intervention by package maintainers and system administrators.

       The  script supplied with the module invokes the shell function zsh-newuser-install.  This may be invoked
       directly by the user even if the zsh/newuser module is disabled.  Note, however, that if  the  module  is
       not  installed the function will not be installed either.  The function is documented in the section User
       Configuration Functions in zshcontrib(1).

THE ZSH/PARAMETER MODULE

       The zsh/parameter module gives access to some of the internal hash tables used by the shell  by  defining
       some special parameters.

       options
              The  keys  for this associative array are the names of the options that can be set and unset using
              the setopt and unsetopt builtins. The value of each key is either the string on if the  option  is
              currently set, or the string off if the option is unset.  Setting a key to one of these strings is
              like  setting or unsetting the option, respectively. Unsetting a key in this array is like setting
              it to the value off.

       commands
              This array gives access to the command hash table. The keys are the names  of  external  commands,
              the  values  are  the  pathnames  of  the  files  that would be executed when the command would be
              invoked. Setting a key in this array defines a new entry in this table in the same way as with the
              hash builtin. Unsetting a key as in `unset "commands[foo]"' removes the entry for  the  given  key
              from the command hash table.

       functions
              This  associative  array maps names of enabled functions to their definitions. Setting a key in it
              is like defining a function with the name given by the key  and  the  body  given  by  the  value.
              Unsetting a key removes the definition for the function named by the key.

       dis_functions
              Like functions but for disabled functions.

       builtins
              This  associative  array  gives information about the builtin commands currently enabled. The keys
              are the names of the builtin commands and the values are either `undefined' for  builtin  commands
              that  will automatically be loaded from a module if invoked or `defined' for builtin commands that
              are already loaded.

       dis_builtins
              Like builtins but for disabled builtin commands.

       reswords
              This array contains the enabled reserved words.

       dis_reswords
              Like reswords but for disabled reserved words.

       patchars
              This array contains the enabled pattern characters.

       dis_patchars
              Like patchars but for disabled pattern characters.

       aliases
              This maps the names of the regular aliases currently enabled to their expansions.

       dis_aliases
              Like aliases but for disabled regular aliases.

       galiases
              Like aliases, but for global aliases.

       dis_galiases
              Like galiases but for disabled global aliases.

       saliases
              Like raliases, but for suffix aliases.

       dis_saliases
              Like saliases but for disabled suffix aliases.

       parameters
              The keys in this associative array are the names of the parameters currently defined.  The  values
              are strings describing the type of the parameter, in the same format used by the t parameter flag,
              see zshexpn(1) .  Setting or unsetting keys in this array is not possible.

       modules
              An  associative  array  giving  information  about  modules. The keys are the names of the modules
              loaded, registered to be autoloaded, or aliased. The value says which state the named module is in
              and is one of the strings `loaded', `autoloaded', or `alias:name', where  name  is  the  name  the
              module is aliased to.

              Setting or unsetting keys in this array is not possible.

       dirstack
              A  normal  array  holding  the  elements  of the directory stack. Note that the output of the dirs
              builtin command includes one more directory, the current working directory.

       history
              This associative array maps history event numbers to the full history lines.

       historywords
              A special array containing the words stored in the history.

       jobdirs
              This associative array maps job numbers to the directories from which the job was  started  (which
              may not be the current directory of the job).

              The  keys of the associative arrays are usually valid job numbers, and these are the values output
              with, for example, ${(k)jobdirs}.  Non-numeric job references may be used when looking up a value;
              for example, ${jobdirs[%+]} refers to the current job.

       jobtexts
              This associative array maps job numbers to the texts of the command lines that were used to  start
              the jobs.

              Handling of the keys of the associative array is as described for jobdirs above.

       jobstates
              This  associative  array  gives information about the states of the jobs currently known. The keys
              are the job numbers and the values are strings  of  the  form  `job-state:mark:pid=state...'.  The
              job-state gives the state the whole job is currently in, one of `running', `suspended', or `done'.
              The  mark  is  `+'  for  the  current  job,  `-' for the previous job and empty otherwise. This is
              followed by one `:pid=state' for every process in the job. The pids are, of  course,  the  process
              IDs and the state describes the state of that process.

              Handling of the keys of the associative array is as described for jobdirs above.

       nameddirs
              This associative array maps the names of named directories to the pathnames they stand for.

       userdirs
              This associative array maps user names to the pathnames of their home directories.

       usergroups
              This  associative  array  maps names of system groups of which the current user is a member to the
              corresponding group identifiers.  The contents are the  same  as  the  groups  output  by  the  id
              command.

       funcfiletrace
              This array contains the absolute line numbers and corresponding file names for the point where the
              current  function, sourced file, or (if EVAL_LINENO is set) eval command was called.  The array is
              of the same length as funcsourcetrace and functrace, but differs from funcsourcetrace in that  the
              line  and  file  are the point of call, not the point of definition, and differs from functrace in
              that all values are absolute line numbers in files,  rather  than  relative  to  the  start  of  a
              function, if any.

       funcsourcetrace
              This  array  contains  the  file names and line numbers of the points where the functions, sourced
              files, and (if EVAL_LINENO is set) eval commands currently being executed were defined.  The  line
              number  is  the line where the `function name' or `name ()' started.  In the case of an autoloaded
              function  the line number is reported as zero.  The format of  each  element  is  filename:lineno.
              For  functions  autoloaded  from  a file in native zsh format, where only the body of the function
              occurs in the file, or for files that have been executed by the source or `.' builtins, the  trace
              information is shown as filename:0, since the entire file is the definition.

              Most users will be interested in the information in the funcfiletrace array instead.

       funcstack
              This  array  contains  the names of the functions, sourced files, and (if EVAL_LINENO is set) eval
              commands. currently being executed. The first element is  the  name  of  the  function  using  the
              parameter.

              The  standard  shell  array  zsh_eval_context can be used to determine the type of shell construct
              being executed at each depth: note, however, that is in the opposite order, with the  most  recent
              item  last,  and  it is more detailed, for example including an entry for toplevel, the main shell
              code being executed either interactively or from a script, which is not present in $funcstack.

       functrace
              This array contains the names and line numbers of  the  callers  corresponding  to  the  functions
              currently  being executed.  The format of each element is name:lineno.  Callers are also shown for
              sourced files; the caller is the point where the source or `.' command was executed.

THE ZSH/PCRE MODULE

       The zsh/pcre module makes some commands available as builtins:

       pcre_compile [ -aimxs ] PCRE
              Compiles a perl-compatible regular expression.

              Option -a will force the pattern to be  anchored.   Option  -i  will  compile  a  case-insensitive
              pattern.  Option -m will compile a multi-line pattern; that is, ^ and $ will match newlines within
              the  pattern.   Option  -x will compile an extended pattern, wherein whitespace and # comments are
              ignored.  Option -s makes the  dot  metacharacter  match  all  characters,  including  those  that
              indicate newline.

       pcre_study
              Studies the previously-compiled PCRE which may result in faster matching.

       pcre_match [ -v var ] [ -a arr ] [ -n offset ] [ -b ] string
              Returns successfully if string matches the previously-compiled PCRE.

              Upon  successful  match, if the expression captures substrings within parentheses, pcre_match will
              set the array match to those substrings, unless the -a option is given, in which case it will  set
              the  array  arr.   Similarly,  the variable MATCH will be set to the entire matched portion of the
              string, unless the -v option is given, in which case the variable var will be set.   No  variables
              are  altered  if  there is no successful match.  A -n option starts searching for a match from the
              byte offset position in string.  If the -b option is given, the variable ZPCRE_OP will be  set  to
              an offset pair string, representing the byte offset positions of the entire matched portion within
              the  string.   For  example, a ZPCRE_OP set to "32 45" indicates that the matched portion began on
              byte offset 32 and ended on byte offset 44.   Here,  byte  offset  position  45  is  the  position
              directly  after  the  matched  portion.  Keep in mind that the byte position isn't necessarily the
              same as the character position when UTF-8 characters are involved.  Consequently, the byte  offset
              positions are only to be relied on in the context of using them for subsequent searches on string,
              using  an  offset  position as an argument to the -n option.  This is mostly used to implement the
              "find all non-overlapping matches" functionality.

              A simple example of "find all non-overlapping matches":

                     string="The following zip codes: 78884 90210 99513"
                     pcre_compile -m "\d{5}"
                     accum=()
                     pcre_match -b -- $string
                     while [[ $? -eq 0 ]] do
                         b=($=ZPCRE_OP)
                         accum+=$MATCH
                         pcre_match -b -n $b[2] -- $string
                     done
                     print -l $accum

       The zsh/pcre module makes available the following test condition:

       expr -pcre-match pcre
              Matches a string against a perl-compatible regular expression.

              For example,

                     [[ "$text" -pcre-match ^d+$ ]] &&
                     print text variable contains only "d's".

              If the REMATCH_PCRE option is  set,  the  =~  operator  is  equivalent  to  -pcre-match,  and  the
              NO_CASE_MATCH  option  may  be  used.   Note  that  NO_CASE_MATCH  never applies to the pcre_match
              builtin, instead use the -i switch of pcre_compile.

THE ZSH/REGEX MODULE

       The zsh/regex module makes available the following test condition:

       expr -regex-match regex
              Matches a string against a POSIX  extended  regular  expression.   On  successful  match,  matched
              portion  of  the string will normally be placed in the MATCH variable.  If there are any capturing
              parentheses within the regex, then the match array variable will contain those.  If the  match  is
              not successful, then the variables will not be altered.

              For example,

                     [[ alphabetical -regex-match ^a([^a]+)a([^a]+)a ]] &&
                     print -l $MATCH X $match

              If the option REMATCH_PCRE is not set, then the =~ operator will automatically load this module as
              needed and will invoke the -regex-match operator.

              If BASH_REMATCH is set, then the array BASH_REMATCH will be set instead of MATCH and match.

THE ZSH/SCHED MODULE

       The zsh/sched module makes available one builtin command and one parameter.

       sched [-o] [+]hh:mm[:ss] command ...
       sched [-o] [+]seconds command ...
       sched [ -item ]
              Make  an  entry in the scheduled list of commands to execute.  The time may be specified in either
              absolute or relative time, and either as hours, minutes and (optionally) seconds  separated  by  a
              colon,  or  seconds  alone.   An  absolute  number  of  seconds indicates the time since the epoch
              (1970/01/01 00:00); this is useful in combination with the features in  the  zsh/datetime  module,
              see the zsh/datetime module entry in zshmodules(1).

              With  no  arguments,  prints  the list of scheduled commands.  If the scheduled command has the -o
              flag set, this is shown at the start of the command.

              With the argument `-item', removes the given item from the list.  The numbering  of  the  list  is
              continuous  and  entries  are in time order, so the numbering can change when entries are added or
              deleted.

              Commands are executed either immediately before a prompt, or while  the  shell's  line  editor  is
              waiting  for  input.   In  the latter case it is useful to be able to produce output that does not
              interfere with the line being edited.  Providing the option -o  causes  the  shell  to  clear  the
              command  line  before  the event and redraw it afterwards.  This should be used with any scheduled
              event that produces visible output to the terminal; it is not needed,  for  example,  with  output
              that updates a terminal emulator's title bar.

              The  sched  builtin  is  not  made  available by default when the shell starts in a mode emulating
              another shell.  It can be made available with the command `zmodload -F zsh/sched b:sched'.

       zsh_scheduled_events
              A readonly array corresponding to the events scheduled by the sched builtin.  The indices  of  the
              array  correspond  to  the  numbers  shown  when sched is run with no arguments (provided that the
              KSH_ARRAYS option is not set).  The value of the array consists of the scheduled time  in  seconds
              since  the epoch (see the section `The zsh/datetime Module' for facilities for using this number),
              followed by a colon, followed by any options (which may be empty but will be  preceded  by  a  `-'
              otherwise), followed by a colon, followed by the command to be executed.

              The  sched  builtin  should  be  used  for  manipulating  the events.  Note that this will have an
              immediate effect on the contents of the array, so that indices may become invalid.

THE ZSH/NET/SOCKET MODULE

       The zsh/net/socket module makes available one builtin command:

       zsocket [ -altv ] [ -d fd ] [ args ]
              zsocket is implemented as a builtin to allow full use of shell command line editing, file I/O, and
              job control mechanisms.

   Outbound Connections
       zsocket [ -v ] [ -d fd ] filename
              Open a new Unix domain connection to filename.  The shell parameter REPLY will be set to the  file
              descriptor associated with that connection.  Currently, only stream connections are supported.

              If -d is specified, its argument will be taken as the target file descriptor for the connection.

              In order to elicit more verbose output, use -v.

   Inbound Connections
       zsocket -l [ -v ] [ -d fd ] filename
              zsocket -l will open a socket listening on filename.  The shell parameter REPLY will be set to the
              file descriptor associated with that listener.

              If -d is specified, its argument will be taken as the target file descriptor for the connection.

              In order to elicit more verbose output, use -v.

       zsocket -a [ -tv ] [ -d targetfd ] listenfd
              zsocket  -a  will accept an incoming connection to the socket associated with listenfd.  The shell
              parameter REPLY will be set to the file descriptor associated with the inbound connection.

              If -d is specified, its argument will be taken as the target file descriptor for the connection.

              If -t is specified, zsocket will return if no incoming connection is pending.  Otherwise  it  will
              wait for one.

              In order to elicit more verbose output, use -v.

THE ZSH/STAT MODULE

       The zsh/stat module makes available one builtin command under two possible names:

       zstat [ -gnNolLtTrs ] [ -f fd ] [ -H hash ] [ -A array ] [ -F fmt ]
             [ +element ] [ file ... ]
       stat ...
              The  command  acts  as  a  front  end  to the stat system call (see stat(2)).  The same command is
              provided with two names; as the name stat is often used by an external command it  is  recommended
              that  only the zstat form of the command is used.  This can be arranged by loading the module with
              the command `zmodload -F zsh/stat b:zstat'.

              If the stat call fails, the appropriate system error message printed and  status  1  is  returned.
              The  fields  of struct stat give information about the files provided as arguments to the command.
              In addition to those available from the stat call, an extra element  `link'  is  provided.   These
              elements are:

              device The number of the device on which the file resides.

              inode  The unique number of the file on this device (`inode' number).

              mode   The mode of the file; that is, the file's type and access permissions.  With the -s option,
                     this  will  be returned as a string corresponding to the first column in the display of the
                     ls -l command.

              nlink  The number of hard links to the file.

              uid    The user ID of the owner of the file.  With the -s option, this  is  displayed  as  a  user
                     name.

              gid    The group ID of the file.  With the -s option, this is displayed as a group name.

              rdev   The raw device number.  This is only useful for special devices.

              size   The size of the file in bytes.

              atime
              mtime
              ctime  The  last  access,  modification  and  inode change times of the file, respectively, as the
                     number of seconds since midnight GMT on 1st January, 1970.  With the -s option,  these  are
                     printed  as  strings for the local time zone; the format can be altered with the -F option,
                     and with the -g option the times are in GMT.

              blksize
                     The number of bytes in one allocation block on the device on which the file resides.

              block  The number of disk blocks used by the file.

              link   If the file is a link and the -L option is in effect, this contains the name  of  the  file
                     linked  to, otherwise it is empty.  Note that if this element is selected (``zstat +link'')
                     then the -L option is automatically used.

              A particular element may be selected by including its name preceded by a `+' in the  option  list;
              only  one  element  is  allowed.   The  element  may  be  shortened  to  any unique set of leading
              characters.  Otherwise, all elements will be shown for all files.

              Options:

              -A array
                     Instead of displaying the results on standard output, assign them to an array,  one  struct
                     stat  element  per  array element for each file in order.  In this case neither the name of
                     the element nor the name of the files appears in array unless the -t  or  -n  options  were
                     given,  respectively.   If  -t  is  given,  the  element  name  appears  as a prefix to the
                     appropriate array element; if -n is given, the  file  name  appears  as  a  separate  array
                     element preceding all the others.  Other formatting options are respected.

              -H hash
                     Similar  to  -A,  but  instead assign the values to hash.  The keys are the elements listed
                     above.  If the -n option is provided then the name of the file is included in the hash with
                     key name.

              -f fd  Use the file on file descriptor fd instead of named files; no list of file names is allowed
                     in this case.

              -F fmt Supplies a strftime (see strftime(3)) string for the formatting of the time elements.   The
                     -s option is implied.

              -g     Show the time elements in the GMT time zone.  The -s option is implied.

              -l     List  the  names  of  the type elements (to standard output or an array as appropriate) and
                     return immediately; options other than -A and arguments are ignored.

              -L     Perform an lstat (see lstat(2)) rather than a stat system call.  In this case, if the  file
                     is a link, information about the link itself rather than the target file is returned.  This
                     option  is  required  to make the link element useful.  It's important to note that this is
                     the exact opposite from ls(1), etc.

              -n     Always show the names of files.  Usually these are only shown when output  is  to  standard
                     output and there is more than one file in the list.

              -N     Never show the names of files.

              -o     If a raw file mode is printed, show it in octal, which is more useful for human consumption
                     than  the default of decimal.  A leading zero will be printed in this case.  Note that this
                     does not affect whether a raw or formatted file mode is shown, which is controlled  by  the
                     -r and -s options, nor whether a mode is shown at all.

              -r     Print  raw data (the default format) alongside string data (the -s format); the string data
                     appears in parentheses after the raw data.

              -s     Print mode, uid, gid and the three time elements as strings instead of  numbers.   In  each
                     case the format is like that of ls -l.

              -t     Always  show  the type names for the elements of struct stat.  Usually these are only shown
                     when output is to standard output and no individual element has been selected.

              -T     Never show the type names of the struct stat elements.

THE ZSH/SYSTEM MODULE

       The zsh/system module makes available various builtin commands and parameters.

   Builtins
       syserror [ -e errvar ] [ -p prefix ] [ errno | errname ]
              This command prints out the error message associated with errno, a system error  number,  followed
              by a newline to standard error.

              Instead of the error number, a name errname, for example ENOENT, may be used.  The set of names is
              the same as the contents of the array errnos, see below.

              If  the  string  prefix is given, it is printed in front of the error message, with no intervening
              space.

              If errvar is supplied, the entire message, without a newline, is assigned to the  parameter  names
              errvar and nothing is output.

              A return status of 0 indicates the message was successfully printed (although it may not be useful
              if the error number was out of the system's range), a return status of 1 indicates an error in the
              parameters,  and  a  return status of 2 indicates the error name was not recognised (no message is
              printed for this).

       sysopen [ -arw ] [ -m permissions ] [ -o options ]
               -u fd file
              This command opens a file. The -r, -w and -a flags indicate whether the file should be opened  for
              reading,  writing and appending, respectively. The -m option allows the initial permissions to use
              when creating a file to be specified in octal form.  The file descriptor  is  specified  with  -u.
              Either  an explicit file descriptor in the range 0 to 9 can be specified or a variable name can be
              given to which the file descriptor number will be assigned.

              The -o option allows various system specific options to be specified as  a  comma-separated  list.
              The  following  is a list of possible options. Note that, depending on the system, some may not be
              available.
              cloexec
                     mark file to be closed when other programs are executed

              create
              creat  create file if it does not exist

              excl   create file, error if it already exists

              noatime
                     suppress updating of the file atime

              nofollow
                     fail if file is a symbolic link

              sync   request that writes wait until data has been physically written

              truncate
              trunc  truncate file to size 0

              To close the file, use one of the following:

                     exec {fd}<&-
                     exec {fd}>&-

       sysread [ -c countvar ] [ -i infd ] [ -o outfd ]
               [ -s bufsize ] [ -t timeout ] [ param ]
              Perform a single system read from file descriptor infd, or zero if that is not given.  The  result
              of the read is stored in param or REPLY if that is not given.  If countvar is given, the number of
              bytes read is assigned to the parameter named by countvar.

              The  maximum  number  of  bytes  read is bufsize or 8192 if that is not given, however the command
              returns as soon as any number of bytes was successfully read.

              If timeout is given, it specifies a timeout in seconds,  which  may  be  zero  to  poll  the  file
              descriptor.   This  is  handled  by the poll system call if available, otherwise the select system
              call if available.

              If outfd is given, an attempt is made to write all the bytes just  read  to  the  file  descriptor
              outfd.   If  this  fails, because of a system error other than EINTR or because of an internal zsh
              error during an interrupt, the bytes read but not written are stored in  the  parameter  named  by
              param  if supplied (no default is used in this case), and the number of bytes read but not written
              is stored in the parameter named by countvar if that is supplied.  If it was successful,  countvar
              contains the full number of bytes transferred, as usual, and param is not set.

              The  error  EINTR  (interrupted  system  call)  is handled internally so that shell interrupts are
              transparent to the caller.  Any other error causes a return.

              The possible return statuses are
              0      At least one byte of data was successfully read and, if appropriate, written.

              1      There was an error in the parameters to the command.  This is the only error  for  which  a
                     message is printed to standard error.

              2      There was an error on the read, or on polling the input file descriptor for a timeout.  The
                     parameter ERRNO gives the error.

              3      Data  were  successfully read, but there was an error writing them to outfd.  The parameter
                     ERRNO gives the error.

              4      The attempt to read timed out.  Note this does not set ERRNO as this is not a system error.

              5      No system error occurred, but zero bytes were read.  This usually indicates  end  of  file.
                     The parameters are set according to the usual rules; no write to outfd is attempted.

       sysseek [ -u fd ] [ -w start|end|current ] offset
              The  current  file  position  at  which future reads and writes will take place is adjusted to the
              specified byte offset. The offset is evaluated as a math expression. The -u option allows the file
              descriptor to be specified. By default the offset is specified relative to the start or  the  file
              but,  with  the  -w  option,  it  is possible to specify that the offset should be relative to the
              current position or the end of the file.

       syswrite [ -c countvar ] [ -o outfd ] data
              The data (a single string of bytes) are written to the file descriptor outfd, or 1 if that is  not
              given,  using  the write system call.  Multiple write operations may be used if the first does not
              write all the data.

              If countvar is given, the number of byte written is stored in the  parameter  named  by  countvar;
              this may not be the full length of data if an error occurred.

              The  error  EINTR  (interrupted system call) is handled internally by retrying; otherwise an error
              causes the command to return.  For example, if the file descriptor is set to non-blocking  output,
              an error EAGAIN (on some systems, EWOULDBLOCK) may result in the command returning early.

              The  return status may be 0 for success, 1 for an error in the parameters to the command, or 2 for
              an error on the write; no error message is printed in the last case, but the parameter ERRNO  will
              reflect the error that occurred.

       zsystem flock [ -t timeout ] [ -f var ] [-er] file
       zsystem flock -u fd_expr
              The  builtin  zsystem's  subcommand  flock performs advisory file locking (via the fcntl(2) system
              call) over the entire contents of the given file.  This form of  locking  requires  the  processes
              accessing  the  file  to  cooperate;  its  most  obvious use is between two instances of the shell
              itself.

              In the first form the named file, which must already exist, is locked by opening a file descriptor
              to the file and applying a lock to the file  descriptor.   The  lock  terminates  when  the  shell
              process  that created the lock exits; it is therefore often convenient to create file locks within
              subshells, since the lock is automatically released when the subshell exits.  Status 0 is returned
              if the lock succeeds, else status 1.

              In the second form the file descriptor given by  the  arithmetic  expression  fd_expr  is  closed,
              releasing  a lock.  The file descriptor can be queried by using the `-f var' form during the lock;
              on a successful lock, the shell variable var is set to the file descriptor used for locking.   The
              lock will be released if the file descriptor is closed by any other means, for example using `exec
              {var}>&-'; however, the form described here performs a safety check that the file descriptor is in
              use for file locking.

              By  default the shell waits indefinitely for the lock to succeed.  The option -t timeout specifies
              a timeout for the lock in seconds; currently this must be an integer.  The shell will  attempt  to
              lock the file once a second during this period.  If the attempt times out, status 2 is returned.

              If  the option -e is given, the file descriptor for the lock is preserved when the shell uses exec
              to start a new process; otherwise it is closed at that point and the lock released.

              If the option -r is given, the lock is only for reading, otherwise it is for reading and  writing.
              The file descriptor is opened accordingly.

       zsystem supports subcommand
              The  builtin  zsystem's  subcommand  supports  tests  whether a given subcommand is supported.  It
              returns status 0 if so, else status 1.  It operates silently unless there was a syntax error (i.e.
              the wrong number of arguments), in which case status 255 is returned.  Status 1 can  indicate  one
              of  two  things:   subcommand  is  known  but  not  supported  by the current operating system, or
              subcommand is not known (possibly because this is an older version of  the  shell  before  it  was
              implemented).

   Math Functions
       systell(fd)
              The  systell  math function returns the current file position for the file descriptor passed as an
              argument.

   Parameters
       errnos A readonly array of the names of errors defined on the system.  These are typically macros defined
              in C by including the system header file errno.h.  The index of each  name  (assuming  the  option
              KSH_ARRAYS  is  unset)  corresponds  to the error number.  Error numbers num before the last known
              error which have no name are given the name Enum in the array.

              Note that aliases for errors are not handled; only the canonical name is used.

       sysparams
              A readonly associative array.  The keys are:

              pid    Returns the process ID of the current  process,  even  in  subshells.   Compare  $$,  which
                     returns the process ID of the main shell process.

              ppid   Returns  the  process  ID of the parent of the current process, even in subshells.  Compare
                     $PPID, which returns the process ID of the parent of the main shell process.

THE ZSH/NET/TCP MODULE

       The zsh/net/tcp module makes available one builtin command:

       ztcp [ -acflLtv ] [ -d fd ] [ args ]
              ztcp is implemented as a builtin to allow full use of shell command line editing,  file  I/O,  and
              job control mechanisms.

              If ztcp is run with no options, it will output the contents of its session table.

              If it is run with only the option -L, it will output the contents of the session table in a format
              suitable  for automatic parsing.  The option is ignored if given with a command to open or close a
              session.  The output consists of a set of lines, one per session, each  containing  the  following
              elements separated by spaces:

              File descriptor
                     The  file  descriptor  in  use for the connection.  For normal inbound (I) and outbound (O)
                     connections this may be read and written by the usual shell mechanisms.  However, it should
                     only be close with `ztcp -c'.

              Connection type
                     A letter indicating how the session was created:

                     Z      A session created with the zftp command.

                     L      A connection opened for listening with `ztcp -l'.

                     I      An inbound connection accepted with `ztcp -a'.

                     O      An outbound connection created with `ztcp host ...'.

              The local host
                     This is usually set to  an  all-zero  IP  address  as  the  address  of  the  localhost  is
                     irrelevant.

              The local port
                     This is likely to be zero unless the connection is for listening.

              The remote host
                     This  is the fully qualified domain name of the peer, if available, else an IP address.  It
                     is an all-zero IP address for a session opened for listening.

              The remote port
                     This is zero for a connection opened for listening.

   Outbound Connections
       ztcp [ -v ] [ -d fd ] host [ port ]
              Open a new TCP connection to host.  If the port is omitted, it  will  default  to  port  23.   The
              connection  will  be  added  to the session table and the shell parameter REPLY will be set to the
              file descriptor associated with that connection.

              If -d is specified, its argument will be taken as the target file descriptor for the connection.

              In order to elicit more verbose output, use -v.

   Inbound Connections
       ztcp -l [ -v ] [ -d fd ] port
              ztcp -l will open a socket listening on TCP port.  The socket will be added to the  session  table
              and the shell parameter REPLY will be set to the file descriptor associated with that listener.

              If -d is specified, its argument will be taken as the target file descriptor for the connection.

              In order to elicit more verbose output, use -v.

       ztcp -a [ -tv ] [ -d targetfd ] listenfd
              ztcp  -a  will accept an incoming connection to the port associated with listenfd.  The connection
              will be added to the session table and  the  shell  parameter  REPLY  will  be  set  to  the  file
              descriptor associated with the inbound connection.

              If -d is specified, its argument will be taken as the target file descriptor for the connection.

              If -t is specified, ztcp will return if no incoming connection is pending.  Otherwise it will wait
              for one.

              In order to elicit more verbose output, use -v.

   Closing Connections
       ztcp -cf [ -v ] [ fd ]
       ztcp -c [ -v ] [ fd ]
              ztcp  -c  will  close  the socket associated with fd.  The socket will be removed from the session
              table.  If fd is not specified, ztcp will close everything in the session table.

              Normally, sockets registered by zftp (see zshmodules(1) ) cannot be closed this way.  In order  to
              force such a socket closed, use -f.

              In order to elicit more verbose output, use -v.

   Example
       Here is how to create a TCP connection between two instances of zsh.  We need to pick an unassigned port;
       here we use the randomly chosen 5123.

       On host1,
              zmodload zsh/net/tcp
              ztcp -l 5123
              listenfd=$REPLY
              ztcp -a $listenfd
              fd=$REPLY
       The second from last command blocks until there is an incoming connection.

       Now create a connection from host2 (which may, of course, be the same machine):
              zmodload zsh/net/tcp
              ztcp host1 5123
              fd=$REPLY

       Now on each host, $fd contains a file descriptor for talking to the other.  For example, on host1:
              print This is a message >&$fd
       and on host2:
              read -r line <&$fd; print -r - $line
       prints `This is a message'.

       To tidy up, on host1:
              ztcp -c $listenfd
              ztcp -c $fd
       and on host2
              ztcp -c $fd

THE ZSH/TERMCAP MODULE

       The zsh/termcap module makes available one builtin command:

       echotc cap [ arg ... ]
              Output the termcap value corresponding to the capability cap, with optional arguments.

       The zsh/termcap module makes available one parameter:

       termcap
              An associative array that maps termcap capability codes to their values.

THE ZSH/TERMINFO MODULE

       The zsh/terminfo module makes available one builtin command:

       echoti cap [ arg ]
              Output  the  terminfo  value  corresponding  to  the  capability  cap,  instantiated  with  arg if
              applicable.

       The zsh/terminfo module makes available one parameter:

       terminfo
              An associative array that maps terminfo capability names to their values.

THE ZSH/ZFTP MODULE

       The zsh/zftp module makes available one builtin command:

       zftp subcommand [ args ]
              The zsh/zftp module is a client for FTP (file transfer protocol).  It is implemented as a  builtin
              to  allow  full  use  of shell command line editing, file I/O, and job control mechanisms.  Often,
              users will access it via shell functions providing a more powerful interface; a  set  is  provided
              with  the  zsh  distribution  and  is  described  in  zshzftpsys(1).  However, the zftp command is
              entirely usable in its own right.

              All commands consist of the command name zftp followed by the name of  a  subcommand.   These  are
              listed  below.  The return status of each subcommand is supposed to reflect the success or failure
              of the remote operation.  See a description of the variable ZFTP_VERBOSE for more  information  on
              how responses from the server may be printed.

   Subcommands
       open host[:port] [ user [ password [ account ] ] ]
              Open  a  new FTP session to host, which may be the name of a TCP/IP connected host or an IP number
              in the standard dot notation.  If the argument is in the form host:port, open a connection to  TCP
              port port instead of the standard FTP port 21.  This may be the name of a TCP service or a number:
              see the description of ZFTP_PORT below for more information.

              If  IPv6  addresses  in  colon  format  are  used,  the host should be surrounded by quoted square
              brackets  to  distinguish  it  from  the  port,  for  example  '[fe80::203:baff:fe02:8b56]'.   For
              consistency this is allowed with all forms of host.

              Remaining arguments are passed to the login subcommand.  Note that if no arguments beyond host are
              supplied,  open will not automatically call login.  If no arguments at all are supplied, open will
              use the parameters set by the params subcommand.

              After a successful open, the shell variables ZFTP_HOST, ZFTP_PORT,  ZFTP_IP  and  ZFTP_SYSTEM  are
              available; see `Variables' below.

       login [ name [ password [ account ] ] ]
       user [ name [ password [ account ] ] ]
              Login  the  user name with parameters password and account.  Any of the parameters can be omitted,
              and will be read from standard input if needed (name is always needed).  If standard  input  is  a
              terminal, a prompt for each one will be printed on standard error and password will not be echoed.
              If any of the parameters are not used, a warning message is printed.

              After  a successful login, the shell variables ZFTP_USER, ZFTP_ACCOUNT and ZFTP_PWD are available;
              see `Variables' below.

              This command may be re-issued when a user is already logged in,  and  the  server  will  first  be
              reinitialized for a new user.

       params [ host [ user [ password [ account ] ] ] ]
       params -
              Store  the  given  parameters for a later open command with no arguments.  Only those given on the
              command line will be remembered.  If no arguments are given,  the  parameters  currently  set  are
              printed,  although  the  password  will  appear as a line of stars; the return status is one if no
              parameters were set, zero otherwise.

              Any of the parameters may be specified as a `?', which may need to be quoted to  protect  it  from
              shell  expansion.   In  this  case,  the appropriate parameter will be read from stdin as with the
              login subcommand, including special handling of password.  If the `?' is  followed  by  a  string,
              that is used as the prompt for reading the parameter instead of the default message (any necessary
              punctuation  and whitespace should be included at the end of the prompt).  The first letter of the
              parameter (only) may be quoted with a `\'; hence an argument "\\$word" guarantees that the  string
              from the shell parameter $word will be treated literally, whether or not it begins with a `?'.

              If  instead  a  single  `-' is given, the existing parameters, if any, are deleted.  In that case,
              calling open with no arguments will cause an error.

              The list of parameters is not deleted after a close, however it will be deleted  if  the  zsh/zftp
              module is unloaded.

              For example,

                     zftp params ftp.elsewhere.xx juser '?Password for juser: '

              will  store  the  host  ftp.elsewhere.xx  and  the  user  juser  and  then prompt the user for the
              corresponding password with the given prompt.

       test   Test the connection; if the server has reported that it has closed the connection (maybe due to  a
              timeout),  return  status 2; if no connection was open anyway, return status 1; else return status
              0.  The test subcommand is silent, apart from messages printed by the $ZFTP_VERBOSE mechanism,  or
              error messages if the connection closes.  There is no network overhead for this test.

              The test is only supported on systems with either the select(2) or poll(2) system calls; otherwise
              the message `not supported on this system' is printed instead.

              The  test  subcommand  will  automatically  be called at the start of any other subcommand for the
              current session when a connection is open.

       cd directory
              Change the remote directory to directory.  Also alters the shell variable ZFTP_PWD.

       cdup   Change the remote directory to the one higher in the directory tree.  Note that cd  ..  will  also
              work correctly on non-UNIX systems.

       dir [ arg ... ]
              Give a (verbose) listing of the remote directory.  The args are passed directly to the server. The
              command's  behaviour  is implementation dependent, but a UNIX server will typically interpret args
              as arguments to the ls command and with no arguments return the result of `ls -l'.  The  directory
              is listed to standard output.

       ls [ arg ... ]
              Give  a (short) listing of the remote directory.  With no arg, produces a raw list of the files in
              the directory, one per line.  Otherwise, up to vagaries  of  the  server  implementation,  behaves
              similar to dir.

       type [ type ]
              Change  the  type  for  the  transfer  to  type, or print the current type if type is absent.  The
              allowed values are `A' (ASCII), `I' (Image, i.e. binary), or `B' (a synonym for `I').

              The FTP default for a transfer is ASCII.  However, if zftp finds that the remote host  is  a  UNIX
              machine  with  8-bit  byes,  it  will automatically switch to using binary for file transfers upon
              open.  This can subsequently be overridden.

              The transfer type is only passed to the remote host when a data connection  is  established;  this
              command involves no network overhead.

       ascii  The same as type A.

       binary The same as type I.

       mode [ S | B ]
              Set  the  mode  type  to  stream  (S) or block (B).  Stream mode is the default; block mode is not
              widely supported.

       remote file ...
       local [ file ... ]
              Print the size and last modification time of the remote or local files.  If there is more than one
              item on the list, the name of the file is printed first.  The first number is the file  size,  the
              second  is the last modification time of the file in the format CCYYMMDDhhmmSS consisting of year,
              month, date, hour, minutes and seconds in GMT.  Note that this format, including  the  length,  is
              guaranteed,  so that time strings can be directly compared via the [[ builtin's < and > operators,
              even if they are too long to be represented as integers.

              Not all servers support the commands for retrieving this information.  In that  case,  the  remote
              command will print nothing and return status 2, compared with status 1 for a file not found.

              The  local  command  (but not remote) may be used with no arguments, in which case the information
              comes from examining file descriptor zero.  This is the same file as seen by a put command with no
              further redirection.

       get file ...
              Retrieve all files from the server, concatenating them and sending them to standard output.

       put file ...
              For each file, read a file from standard input and send that to the remote  host  with  the  given
              name.

       append file ...
              As put, but if the remote file already exists, data is appended to it instead of overwriting it.

       getat file point
       putat file point
       appendat file point
              Versions  of  get,  put  and append which will start the transfer at the given point in the remote
              file.  This is useful for appending to an incomplete local file.  However, note that this  ability
              is  not  universally  supported  by  servers  (and  is  not  quite  the behaviour specified by the
              standard).

       delete file ...
              Delete the list of files on the server.

       mkdir directory
              Create a new directory directory on the server.

       rmdir directory
              Delete the directory directory  on the server.

       rename old-name new-name
              Rename file old-name to new-name on the server.

       site arg ...
              Send a host-specific command to the server.  You will probably only need this if instructed by the
              server to use it.

       quote arg ...
              Send the raw FTP command sequence to the server.  You should be familiar with the FTP command  set
              as defined in RFC959 before doing this.  Useful commands may include STAT and HELP.  Note also the
              mechanism  for  returning messages as described for the variable ZFTP_VERBOSE below, in particular
              that all messages from the control connection are sent to standard error.

       close
       quit   Close the current data  connection.   This  unsets  the  shell  parameters  ZFTP_HOST,  ZFTP_PORT,
              ZFTP_IP, ZFTP_SYSTEM, ZFTP_USER, ZFTP_ACCOUNT, ZFTP_PWD, ZFTP_TYPE and ZFTP_MODE.

       session [ sessname ]
              Allows  multiple  FTP sessions to be used at once.  The name of the session is an arbitrary string
              of characters; the default session is called `default'.  If this  command  is  called  without  an
              argument,  it  will  list all the current sessions; with an argument, it will either switch to the
              existing session called sessname, or create a new session of that name.

              Each session remembers the  status  of  the  connection,  the  set  of  connection-specific  shell
              parameters  (the  same  set  as are unset when a connection closes, as given in the description of
              close), and any user parameters specified with the params  subcommand.   Changing  to  a  previous
              session  restores  those  values; changing to a new session initialises them in the same way as if
              zftp had just  been  loaded.   The  name  of  the  current  session  is  given  by  the  parameter
              ZFTP_SESSION.

       rmsession [ sessname ]
              Delete  a session; if a name is not given, the current session is deleted.  If the current session
              is deleted, the earliest existing session becomes the new current session, otherwise  the  current
              session  is  not  changed.   If  the  session  being deleted is the only one, a new session called
              `default' is created and becomes the current session; note that this is a new session even if  the
              session  being  deleted  is  also called `default'. It is recommended that sessions not be deleted
              while background commands which use zftp are still active.

   Parameters
       The following shell parameters are used by zftp.  Currently none of them are special.

       ZFTP_TMOUT
              Integer.  The time in seconds to wait for a network operation  to  complete  before  returning  an
              error.   If  this  is not set when the module is loaded, it will be given the default value 60.  A
              value of zero turns off timeouts.  If a timeout occurs  on  the  control  connection  it  will  be
              closed.  Use a larger value if this occurs too frequently.

       ZFTP_IP
              Readonly.  The IP address of the current connection in dot notation.

       ZFTP_HOST
              Readonly.   The  hostname  of  the current remote server.  If the host was opened as an IP number,
              ZFTP_HOST contains that instead; this saves the overhead for a name lookup, as IP numbers are most
              commonly used when a nameserver is unavailable.

       ZFTP_PORT
              Readonly.  The number of the remote TCP port to which the connection is open (even if the port was
              originally specified as a named service).  Usually this is the standard FTP port, 21.

              In the unlikely event that your system does not have the appropriate  conversion  functions,  this
              appears  in  network  byte  order.  If your system is little-endian, the port then consists of two
              swapped bytes and the standard port will be reported as 5376.  In that case, numeric ports  passed
              to zftp open will also need to be in this format.

       ZFTP_SYSTEM
              Readonly.   The system type string returned by the server in response to an FTP SYST request.  The
              most interesting case is a string beginning "UNIX Type: L8", which ensures  maximum  compatibility
              with a local UNIX host.

       ZFTP_TYPE
              Readonly.   The  type to be used for data transfers , either `A' or `I'.   Use the type subcommand
              to change this.

       ZFTP_USER
              Readonly.  The username currently logged in, if any.

       ZFTP_ACCOUNT
              Readonly.  The account name of the current user, if any.  Most servers do not require  an  account
              name.

       ZFTP_PWD
              Readonly.  The current directory on the server.

       ZFTP_CODE
              Readonly.  The three digit code of the last FTP reply from the server as a string.  This can still
              be read after the connection is closed, and is not changed when the current session changes.

       ZFTP_REPLY
              Readonly.   The  last line of the last reply sent by the server.  This can still be read after the
              connection is closed, and is not changed when the current session changes.

       ZFTP_SESSION
              Readonly.  The name of the current FTP session; see the description of the session subcommand.

       ZFTP_PREFS
              A string of preferences for altering aspects of zftp's behaviour.  Each  preference  is  a  single
              character.  The following are defined:

              P      Passive:  attempt to make the remote server initiate data transfers.  This is slightly more
                     efficient  than  sendport  mode.  If the letter S occurs later in the string, zftp will use
                     sendport mode if passive mode is not available.

              S      Sendport:  initiate transfers by the FTP PORT command.  If this occurs before any P in  the
                     string, passive mode will never be attempted.

              D      Dumb:   use only the bare minimum of FTP commands.  This prevents the variables ZFTP_SYSTEM
                     and ZFTP_PWD from being set, and will mean all connections default to ASCII type.   It  may
                     prevent  ZFTP_SIZE  from  being set during a transfer if the server does not send it anyway
                     (many servers do).

              If ZFTP_PREFS is not set when zftp is loaded, it will be set  to  a  default  of  `PS',  i.e.  use
              passive mode if available, otherwise fall back to sendport mode.

       ZFTP_VERBOSE
              A string of digits between 0 and 5 inclusive, specifying which responses from the server should be
              printed.   All responses go to standard error.  If any of the numbers 1 to 5 appear in the string,
              raw responses from the server with reply codes beginning  with  that  digit  will  be  printed  to
              standard  error.  The first digit of the three digit reply code is defined by RFC959 to correspond
              to:

              1.     A positive preliminary reply.

              2.     A positive completion reply.

              3.     A positive intermediate reply.

              4.     A transient negative completion reply.

              5.     A permanent negative completion reply.

              It should be noted that, for unknown reasons, the reply  `Service  not  available',  which  forces
              termination  of  a  connection,  is  classified  as 421, i.e. `transient negative', an interesting
              interpretation of the word `transient'.

              The code 0 is special:  it indicates that all but the last line of multiline replies read from the
              server will be printed to standard error in a processed format.  By convention, servers  use  this
              mechanism for sending information for the user to read.  The appropriate reply code, if it matches
              the same response, takes priority.

              If  ZFTP_VERBOSE  is  not  set when zftp is loaded, it will be set to the default value 450, i.e.,
              messages destined for the user and all errors will  be  printed.   A  null  string  is  valid  and
              specifies that no messages should be printed.

   Functions
       zftp_chpwd
              If  this function is set by the user, it is called every time the directory changes on the server,
              including when a user is logged in, or when a connection is closed.  In the last  case,  $ZFTP_PWD
              will be unset; otherwise it will reflect the new directory.

       zftp_progress
              If  this function is set by the user, it will be called during a get, put or append operation each
              time sufficient data has been received from the host.  During a get, the data is sent to  standard
              output,  so  it  is  vital  that  this  function should write to standard error or directly to the
              terminal, not to standard output.

              When it is called with a transfer in progress, the following additional shell parameters are set:

              ZFTP_FILE
                     The name of the remote file being transferred from or to.

              ZFTP_TRANSFER
                     A G for a get operation and a P for a put operation.

              ZFTP_SIZE
                     The total size of the complete file being transferred: the same as the first value provided
                     by the remote and local subcommands for a particular file.  If  the  server  cannot  supply
                     this  value for a remote file being retrieved, it will not be set.  If input is from a pipe
                     the value may be incorrect and correspond simply to a full pipe buffer.

              ZFTP_COUNT
                     The amount of data so far transferred; a number between zero and  $ZFTP_SIZE,  if  that  is
                     set.  This number is always available.

              The  function is initially called with ZFTP_TRANSFER set appropriately and ZFTP_COUNT set to zero.
              After the transfer is finished, the function will be called one more time with  ZFTP_TRANSFER  set
              to GF or PF, in case it wishes to tidy up.  It is otherwise never called twice with the same value
              of ZFTP_COUNT.

              Sometimes  the  progress  meter  may cause disruption.  It is up to the user to decide whether the
              function should be defined and to use unfunction when necessary.

   Problems
       A connection may not be opened in the left hand side of a pipe as this occurs in a subshell and the  file
       information  is  not  updated  in  the  main  shell.   In the case of type or mode changes or closing the
       connection in a subshell, the information is returned but variables are not updated until the  next  call
       to zftp.  Other status changes in subshells will not be reflected by changes to the variables (but should
       be otherwise harmless).

       Deleting  sessions  while a zftp command is active in the background can have unexpected effects, even if
       it does not use the session being deleted.  This is because all shell subprocesses share  information  on
       the state of all connections, and deleting a session changes the ordering of that information.

       On  some  operating  systems,  the  control connection is not valid after a fork(), so that operations in
       subshells, on the left hand side of a pipeline, or in the background are not possible, as they should be.
       This is presumably a bug in the operating system.

THE ZSH/ZLE MODULE

       The zsh/zle module contains the Zsh Line Editor.  See zshzle(1).

THE ZSH/ZLEPARAMETER MODULE

       The zsh/zleparameter module  defines  two  special  parameters  that  can  be  used  to  access  internal
       information of the Zsh Line Editor (see zshzle(1)).

       keymaps
              This array contains the names of the keymaps currently defined.

       widgets
              This  associative  array  contains one entry per widget defined. The name of the widget is the key
              and the value gives information about the widget. It is either the string  `builtin'  for  builtin
              widgets,  a string of the form `user:name' for user-defined widgets, where name is the name of the
              shell function implementing the widget, or it is a string of the form `completion:type:name',  for
              completion widgets. In the last case type is the name of the builtin widgets the completion widget
              imitates  in  its  behavior and name is the name of the shell function implementing the completion
              widget.

THE ZSH/ZPROF MODULE

       When loaded, the zsh/zprof causes shell functions to be profiled.  The profiling results can be  obtained
       with  the  zprof  builtin  command  made available by this module.  There is no way to turn profiling off
       other than unloading the module.

       zprof [ -c ]
              Without the -c option, zprof lists profiling results to standard output.  The format is comparable
              to that of commands like gprof.

              At the top there is a summary listing all functions that were called at least once.  This  summary
              is  sorted  in decreasing order of the amount of time spent in each.  The lines contain the number
              of the function in order, which is used in other parts  of  the  list  in  suffixes  of  the  form
              `[num]',  then  the number of calls made to the function.  The next three columns list the time in
              milliseconds spent in the function and its descendants, the average time in milliseconds spent  in
              the  function and its descendants per call and the percentage of time spent in all shell functions
              used in this function and its descendants.  The following three columns give the same information,
              but counting only the time spent in the function itself.  The final column shows the name  of  the
              function.

              After the summary, detailed information about every function that was invoked is listed, sorted in
              decreasing  order of the amount of time spent in each function and its descendants.  Each of these
              entries consists of descriptions for  the  functions  that  called  the  function  described,  the
              function  itself,  and  the  functions that were called from it.  The description for the function
              itself has the same format as in the summary (and shows the same information).   The  other  lines
              don't  show  the number of the function at the beginning and have their function named indented to
              make it easier to distinguish the line showing the function described  in  the  section  from  the
              surrounding lines.

              The  information  shown  in this case is almost the same as in the summary, but only refers to the
              call hierarchy being displayed.  For example, for a calling function the column showing the  total
              running time lists the time spent in the described function and its descendants only for the times
              when  it  was called from that particular calling function.  Likewise, for a called function, this
              columns lists the total time spent in the called function and its descendants only for  the  times
              when it was called from the function described.

              Also  in  this  case,  the column showing the number of calls to a function also shows a slash and
              then the total number of invocations made to the called function.

              As long as the zsh/zprof module is loaded, profiling will be done and multiple invocations of  the
              zprof  builtin command will show the times and numbers of calls since the module was loaded.  With
              the -c option, the zprof builtin command will reset its internal counters and will  not  show  the
              listing.

THE ZSH/ZPTY MODULE

       The zsh/zpty module offers one builtin:

       zpty [ -e ] [ -b ] name [ arg ... ]
              The  arguments following name are concatenated with spaces between, then executed as a command, as
              if passed to the eval builtin.  The command runs under a newly assigned pseudo-terminal;  this  is
              useful  for  running commands non-interactively which expect an interactive environment.  The name
              is not part of the command, but is used to refer to this command in later calls to zpty.

              With the -e option, the pseudo-terminal is set up so that input characters are echoed.

              With the -b option, input to and output from the pseudo-terminal are made non-blocking.

              The shell parameter REPLY is set to the file  descriptor  assigned  to  the  master  side  of  the
              pseudo-terminal.   This  allows  the  terminal  to  be monitored with ZLE descriptor handlers (see
              zshzle(1)) or manipulated with sysread and syswrite (see THE ZSH/SYSTEM MODULE in  zshmodules(1)).
              Warning:  Use  of sysread and syswrite is not recommended, use zpty -r and zpty -w unless you know
              exactly what you are doing.

       zpty -d [ name ... ]
              The second form, with the -d option, is used to delete commands previously started, by supplying a
              list of their names.  If no name is given, all commands are deleted.  Deleting  a  command  causes
              the HUP signal to be sent to the corresponding process.

       zpty -w [ -n ] name [ string ... ]
              The  -w  option  can  be used to send the to command name the given strings as input (separated by
              spaces).  If the -n option is not given, a newline is added at the end.

              If no string is provided, the standard input is copied  to  the  pseudo-terminal;  this  may  stop
              before copying the full input if the pseudo-terminal is non-blocking.

              Note  that  the  command  under the pseudo-terminal sees this input as if it were typed, so beware
              when sending special tty driver characters such as word-erase, line-kill, and end-of-file.

       zpty -r [ -mt ] name [ param [ pattern ] ]
              The -r option can be used to read the output of the command name.  With only a name argument,  the
              output read is copied to the standard output.  Unless the pseudo-terminal is non-blocking, copying
              continues  until  the  command  under  the  pseudo-terminal exits; when non-blocking, only as much
              output as is immediately available is copied.  The return status is zero if any output is copied.

              When also given a param argument, at most one line is read  and  stored  in  the  parameter  named
              param.   Less  than  a  full  line may be read if the pseudo-terminal is non-blocking.  The return
              status is zero if at least one character is stored in param.

              If a pattern is given as well, output is read until the whole string  read  matches  the  pattern,
              even  in the non-blocking case.  The return status is zero if the string read matches the pattern,
              or if the command has exited but at least one character could still be read.  If the option -m  is
              present,  the return status is zero only if the pattern matches.  As of this writing, a maximum of
              one megabyte of output can be consumed this way; if a full megabyte is read without  matching  the
              pattern, the return status is non-zero.

              In  all cases, the return status is non-zero if nothing could be read, and is 2 if this is because
              the command has finished.

              If the -r option is combined with the -t option, zpty tests whether  output  is  available  before
              trying to read.  If no output is available, zpty immediately returns the status 1.  When used with
              a  pattern,  the behaviour on a failed poll is similar to when the command has exited:  the return
              value is zero if at least one character could still be read even if the pattern failed to match.

       zpty -t name
              The -t option without the -r option can be used to test whether the command name is still running.
              It returns a zero status if the command is running and a non-zero value otherwise.

       zpty [ -L ]
              The last form, without any arguments, is used to list the commands currently defined.  If  the  -L
              option is given, this is done in the form of calls to the zpty builtin.

THE ZSH/ZSELECT MODULE

       The zsh/zselect module makes available one builtin command:

       zselect [ -rwe ] [ -t timeout ] [ -a array ] [ -A assoc ] [ fd ... ]
              The  zselect  builtin  is  a  front-end  to  the  `select'  system call, which blocks until a file
              descriptor is ready for reading or writing, or has an error condition, with an  optional  timeout.
              If  this is not available on your system, the command prints an error message and returns status 2
              (normal errors return status 1).   For  more  information,  see  your  systems  documentation  for
              select(3).  Note there is no connection with the shell builtin of the same name.

              Arguments  and  options  may  be  intermingled  in  any  order.   Non-option  arguments  are  file
              descriptors, which must be decimal integers.  By default, file descriptors are to  be  tested  for
              reading,  i.e.  zselect will return when data is available to be read from the file descriptor, or
              more precisely, when a read operation from the file descriptor will not block.  After a -r, -w and
              -e, the given file descriptors are to be tested for reading, writing, or error conditions.   These
              options and an arbitrary list of file descriptors may be given in any order.

              (The  presence  of  an  `error  condition'  is  not  well  defined  in  the documentation for many
              implementations  of  the  select  system  call.   According  to  recent  versions  of  the   POSIX
              specification,  it  is  really  an  exception  condition,  of  which  the only standard example is
              out-of-band data received on a socket.  So zsh users are unlikely to find the -e option useful.)

              The option `-t timeout' specifies a timeout in hundredths of a second.  This may be zero, in which
              case the file descriptors will simply be polled  and  zselect  will  return  immediately.   It  is
              possible  to  call  zselect  with  no  file  descriptors  and  a  non-zero  timeout  for  use as a
              finer-grained replacement for `sleep'; note, however, the return status is always 1 for a timeout.

              The option `-a array' indicates that array should be set to indicate the file descriptor(s)  which
              are  ready.  If the option is not given, the array reply will be used for this purpose.  The array
              will contain a string similar to the arguments for zselect.  For example,

                     zselect -t 0 -r 0 -w 1

              might return immediately with status 0 and $reply containing `-r 0 -w 1' to show  that  both  file
              descriptors are ready for the requested operations.

              The  option  `-A  assoc'  indicates that the associative array assoc should be set to indicate the
              file descriptor(s) which are ready.  This option overrides  the  option  -a,  nor  will  reply  be
              modified.  The keys of assoc are the file descriptors, and the corresponding values are any of the
              characters `rwe' to indicate the condition.

              The  command  returns  status  0 if some file descriptors are ready for reading.  If the operation
              timed out, or a timeout of 0 was given and no file descriptors were ready, or there was an  error,
              it  returns  status  1  and  the array will not be set (nor modified in any way).  If there was an
              error in the select operation the appropriate error message is printed.

THE ZSH/ZUTIL MODULE

       The zsh/zutil module only adds some builtins:

       zstyle [ -L [ pattern [ style ] ] ]
       zstyle [ -e | - | -- ] pattern style string ...
       zstyle -d [ pattern [ style ... ] ]
       zstyle -g name [ pattern [ style ] ]
       zstyle -{a|b|s} context style name [ sep ]
       zstyle -{T|t} context style [ string ... ]
       zstyle -m context style pattern
              This builtin command is used to define and lookup styles.  Styles are pairs of names  and  values,
              where  the  values  consist  of any number of strings.  They are stored together with patterns and
              lookup is done by giving a string, called the `context', which is compared to the  patterns.   The
              definition stored for the first matching pattern will be returned.

              For  ordering  of  comparisons,  patterns  are  searched from most specific to least specific, and
              patterns that are equally specific keep the order in  which  they  were  defined.   A  pattern  is
              considered  to  be more specific than another if it contains more components (substrings separated
              by colons) or if the patterns for the components are  more  specific,  where  simple  strings  are
              considered  to  be  more  specific  than  patterns  and complex patterns are considered to be more
              specific than the pattern `*'.

              The first form (without arguments) lists the definitions.  Styles are shown  in  alphabetic  order
              and patterns are shown in the order zstyle will test them.

              If  the  -L  option  is given, listing is done in the form of calls to zstyle.  The optional first
              argument is a pattern which will be matched against the string supplied as  the  pattern  for  the
              context;  note  that  this means, for example, `zstyle -L ":completion:*"' will match any supplied
              pattern beginning `:completion:', not just ":completion:*":  use ":completion:\*" to  match  that.
              The  optional  second  argument  limits the output to a specific style (not a pattern).  -L is not
              compatible with any other options.

              The other forms are the following:

              zstyle [ - | -- | -e ] pattern style string ...
                     Defines the given style for the pattern with the strings as the value.  If the -e option is
                     given, the strings will be concatenated (separated by spaces) and the resulting string will
                     be evaluated (in the same way as it is done by the eval builtin command) when the style  is
                     looked up.  In this case the parameter `reply' must be assigned to set the strings returned
                     after  the  evaluation.   Before  evaluating  the value, reply is unset, and if it is still
                     unset after the evaluation, the style is treated as if it were not set.

              zstyle -d [ pattern [ style ... ] ]
                     Delete style definitions. Without arguments all definitions are deleted, with a pattern all
                     definitions for that pattern are deleted and if any  styles  are  given,  then  only  those
                     styles are deleted for the pattern.

              zstyle -g name [ pattern [ style ] ]
                     Retrieve  a style definition. The name is used as the name of an array in which the results
                     are stored. Without any further arguments,  all  patterns  defined  are  returned.  With  a
                     pattern  the  styles  defined  for  that pattern are returned and with both a pattern and a
                     style, the value strings of that combination is returned.

              The other forms can be used to look up or test patterns.

              zstyle -s context style name [ sep ]
                     The parameter name is set to the value of the style interpreted as a string.  If the  value
                     contains  several strings they are concatenated with spaces (or with the sep string if that
                     is given) between them.

              zstyle -b context style name
                     The value is stored in name as a boolean, i.e. as the string `yes' if the  value  has  only
                     one  string and that string is equal to one of `yes', `true', `on', or `1'. If the value is
                     any other string or has more than one string, the parameter is set to `no'.

              zstyle -a context style name
                     The value is stored in name as an array. If name is declared as an associative array,   the
                     first,  third,  etc.  strings  are  used  as the keys and the other strings are used as the
                     values.

              zstyle -t context style [ string ... ]
              zstyle -T context style [ string ... ]
                     Test the value of a style, i.e. the -t option only returns a status (sets $?).  Without any
                     string the return status is zero if the style is defined for at least one matching pattern,
                     has only one string in its value, and that is equal to one of `true', `yes', `on'  or  `1'.
                     If  any  strings are given the status is zero if and only if at least one of the strings is
                     equal to at least one of the strings in the value. If the  style  is  defined  but  doesn't
                     match, the return status is 1. If the style is not defined, the status is 2.

                     The  -T  option  tests  the values of the style like -t, but it returns status zero (rather
                     than 2) if the style is not defined for any matching pattern.

              zstyle -m context style pattern
                     Match a value. Returns status zero if the pattern matches at least one of  the  strings  in
                     the value.

       zformat -f param format spec ...
       zformat -a array sep spec ...
              This  builtin  provides  two different forms of formatting. The first form is selected with the -f
              option. In this case the format string will be modified by replacing  sequences  starting  with  a
              percent  sign  in  it  with strings from the specs.  Each spec should be of the form `char:string'
              which will cause every appearance of the sequence `%char' in format to be replaced by the  string.
              The  `%' sequence may also contain optional minimum and maximum field width specifications between
              the `%' and the `char' in the form `%min.maxc', i.e. the minimum field width is given first and if
              the maximum field width is used, it has to be preceded by a dot.  Specifying a minimum field width
              makes the result be padded with spaces to the right if the string is shorter  than  the  requested
              width.   Padding  to  the  left  can  be  achieved by giving a negative minimum field width.  If a
              maximum field width is specified, the string will be truncated after that many characters.   After
              all  `%'  sequences for the given specs have been processed, the resulting string is stored in the
              parameter param.

              The %-escapes also understand ternary expressions in the form used by prompts.  The % is  followed
              by  a  `(' and then an ordinary format specifier character as described above.  There may be a set
              of digits either before or after the `('; these specify a test number,  which  defaults  to  zero.
              Negative numbers are also allowed.  An arbitrary delimiter character follows the format specifier,
              which  is  followed  by  a piece of `true' text, the delimiter character again, a piece of `false'
              text, and a closing parenthesis.  The complete expression (without the  digits)  thus  looks  like
              `%(X.text1.text2)',  except  that  the `.' character is arbitrary.  The value given for the format
              specifier in the char:string expressions is evaluated as a mathematical expression,  and  compared
              with the test number.  If they are the same, text1 is output, else text2 is output.  A parenthesis
              may be escaped in text2 as %).  Either of text1 or text2 may contain nested %-escapes.

              For example:

                     zformat -f REPLY "The answer is '%3(c.yes.no)'." c:3

              outputs  "The answer is 'yes'." to REPLY since the value for the format specifier c is 3, agreeing
              with the digit argument to the ternary expression.

              The second form, using the -a option, can be used for aligning strings.  Here, the  specs  are  of
              the  form `left:right' where `left' and `right' are arbitrary strings.  These strings are modified
              by replacing the colons by the sep string and padding the left strings with spaces to the right so
              that the sep strings in the result (and hence the right strings after them) are all aligned if the
              strings are printed below each other.  All strings without a colon  are  left  unchanged  and  all
              strings  with an empty right string have the trailing colon removed.  In both cases the lengths of
              the strings are not used to determine how the other strings are  to  be  aligned.   The  resulting
              strings are stored in the array.

       zregexparse
              This implements some internals of the _regex_arguments function.

       zparseopts [ -DKME ] [ -a array ] [ -A assoc ] spec ...
              This builtin simplifies the parsing of options in positional parameters, i.e. the set of arguments
              given  by $*.  Each spec describes one option and must be of the form `opt[=array]'.  If an option
              described by opt is found in the positional parameters it is copied into the array specified  with
              the -a option; if the optional `=array' is given, it is instead copied into that array.

              Note  that  it is an error to give any spec without an `=array' unless one of the -a or -A options
              is used.

              Unless the -E option is given, parsing stops at the first string that isn't described  by  one  of
              the specs.  Even with -E, parsing always stops at a positional parameter equal to `-' or `--'.

              The opt description must be one of the following.  Any of the special characters can appear in the
              option name provided it is preceded by a backslash.

              name
              name+  The  name  is  the name of the option without the leading `-'.  To specify a GNU-style long
                     option, one of the usual two leading `-' must be included in name; for example, a  `--file'
                     option is represented by a name of `-file'.

                     If  a  `+' appears after name, the option is appended to array each time it is found in the
                     positional parameters; without the `+' only the last occurrence of the option is preserved.

                     If one of these forms is used, the option takes no argument, so parsing stops if  the  next
                     positional parameter does not also begin with `-' (unless the -E option is used).

              name:
              name:-
              name:: If  one or two colons are given, the option takes an argument; with one colon, the argument
                     is mandatory and with two colons it is optional.  The argument is  appended  to  the  array
                     after the option itself.

                     An  optional argument is put into the same array element as the option name (note that this
                     makes empty strings as arguments indistinguishable).  A mandatory argument is  added  as  a
                     separate  element  unless the `:-' form is used, in which case the argument is put into the
                     same element.

                     A `+' as described above may appear between the name and the first colon.

              The options of zparseopts itself are:

              -a array
                     As described above, this names the default array in which to store the recognised options.

              -A assoc
                     If this is given, the options and their values are also put into an associative array  with
                     the option names as keys and the arguments (if any) as the values.

              -D     If  this  option  is given, all options found are removed from the positional parameters of
                     the calling shell or shell function, up to but not  including  any  not  described  by  the
                     specs.  This is similar to using the shift builtin.

              -K     With  this  option, the arrays specified with the -a option and with the `=array' forms are
                     kept unchanged when none of the specs for them is used.   Otherwise  the  entire  array  is
                     replaced  when  any  of  the  specs  is  used.   Individual  elements of associative arrays
                     specified with the -A option are preserved by -K.  This allows assignment of default values
                     to arrays before calling zparseopts.

              -M     This changes the assignment rules to implement a map among equivalent option names.  If any
                     spec uses the `=array' form, the string array is interpreted as the name of  another  spec,
                     which  is  used to choose where to store the values.  If no other spec is found, the values
                     are stored as usual.  This changes only the way the values are stored, not the  way  $*  is
                     parsed, so results may be unpredictable if the `name+' specifier is used inconsistently.

              -E     This  changes the parsing rules to not stop at the first string that isn't described by one
                     of the specs.  It can be used to test for or (if used together with -D) extract options and
                     their arguments, ignoring all other options and arguments that may  be  in  the  positional
                     parameters.

              For example,

                     set -- -a -bx -c y -cz baz -cend
                     zparseopts a=foo b:=bar c+:=bar

              will have the effect of

                     foo=(-a)
                     bar=(-b x -c y -c z)

              The arguments from `baz' on will not be used.

              As an example for the -E option, consider:

                     set -- -a x -b y -c z arg1 arg2
                     zparseopts -E -D b:=bar

              will have the effect of

                     bar=(-b y)
                     set -- -a x -c z arg1 arg2

              I.e.,  the  option  -b and its arguments are taken from the positional parameters and put into the
              array bar.

              The -M option can be used like this:

                     set -- -a -bx -c y -cz baz -cend
                     zparseopts -A bar -M a=foo b+: c:=b

              to have the effect of

                     foo=(-a)
                     bar=(-a '' -b xyz)

zsh 5.1.1                                      September 11, 2015                                  ZSHMODULES(1)